jackson-databind's renamed @JsonIgnore'd setters can deserialize via private fields

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

• CVE-2026-54516: 0.45% estimated exploitation activity in the next 30 days; percentile 39.08 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary POJOPropertiesCollector.renameProperties() allows a property with @JsonProperty("renamed") on the getter and @JsonIgnore on the setter to be renamed rather than dropped. With MapperFeature.INFERPROPERTYMUTATORS enabled (default), the private backing field is retained; during deserialization BeanDeserializerFactory.addBeanProps() sees hasField()==true, builds a FieldProperty, and makes the backing field writable. An attacker supplying the renamed JSON key writes the backing field directly, bypassing the @JsonIgnore on the setter. Impact POJOs combining a renamed getter with an ignored setter (a read-only-over-the-wire pattern) have that field silently set from attacker input (property tampering / mass assignment). Not a general gadget; no RCE. Affected / Patched (verified via git tag --contains) - 2.21 line: = 2.21.0, < 2.21.4 - fixed in 2.21.4 (backport c3d56dd, #5968) - 3.x line: = 3.0.0, < 3.1.4 - fixed in 3.1.4 (#5967, e88cb17) Severity / CWE Maintainer: minor. Reporter:…

Published by the source

23 Jun 2026, 21:24 UTC

Last modified by the source

20 Jul 2026, 21:21 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9fxm-vc8v-hj55

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# Patch Next advisory brief: CVE-2026-54516

Advisory: jackson-databind's renamed @JsonIgnore'd setters can deserialize via private fields
IDs: CVE-2026-54516, GHSA-9fxm-vc8v-hj55
Record: https://patchnext.com/advisories/cve-2026-54516 (revision 1, source checked 26 Oct 2026, 16:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tools.jackson.core:jackson-databind 3.1.4; com.fasterxml.jackson.core:jackson-databind 3.1.4, 2.21.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven tools.jackson.core:jackson-databind: affected >= 3.0.0, < 3.1.4; fixed in 3.1.4
- Maven com.fasterxml.jackson.core:jackson-databind: affected >= 2.21.0, < 2.21.4; >= 3.0.0, < 3.1.4; fixed in 2.21.4, 3.1.4

## Suggested inspection (read-only)
- Maven tools.jackson.core:jackson-databind: check the installed version with your package manager.
- Maven com.fasterxml.jackson.core:jackson-databind: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on tools.jackson.core:jackson-databind, com.fasterxml.jackson.core:jackson-databind.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-9fxm-vc8v-hj55 (GitHub-reviewed advisory GHSA-9fxm-vc8v-hj55 lists affected ranges: Maven com.fasterxml.jackson.core:jackson-databind >=2.21.0 =3.0.0 =3.0.0 <3.1.4)

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