jackson-databind: @JsonView bypass for creator properties with @JsonTypeInfo(include=As.EXTERNAL_PROPERTY)

Exploitation

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

CVSS

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary In BeanDeserializer.deserializeUsingPropertyBasedWithExternalTypeId, the active-view (@JsonView) filter was applied only to the regular bean-property branch; the creator-property branch performed no creatorProp.visibleInView(activeView) check. A constructor parameter annotated with both @JsonView(RestrictedView.class) and @JsonTypeInfo(use=Id.NAME, include=As.EXTERNALPROPERTY) is populated from attacker JSON even when a more restrictive view is active. This is a patch gap. GHSA-5hh8 (CVE-2026-54517) and GHSA-rcqc (CVE-2026-54518) descriptions cover only the main property-based path and the unwrapped-creator path respectively; the external-type-id creator path was fixed on the 3.x line via #6004 ("Extend #5969/#5971 fixes to ... external-type-id case in regular BeanDeserializer", commit 7dc7a17, 2026-05-22) but the fix was never backported to 2.21 or 2.18. Users on 2.21.4 and 2.18.8 who upgraded per the published advisories remain vulnerable to the same @JsonView bypass…

Published by the source

21 Jul 2026, 19:40 UTC

Last modified by the source

21 Jul 2026, 19:40 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mhm7-754m-9p8w

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-mhm7-754m-9p8w

Advisory: jackson-databind: `@JsonView` bypass for creator properties with `@JsonTypeInfo(include=As.EXTERNAL_PROPERTY)`
IDs: GHSA-mhm7-754m-9p8w
Record: https://patchnext.com/advisories/ghsa-mhm7-754m-9p8w (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 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: com.fasterxml.jackson.core:jackson-databind 2.21.5, 2.18.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven com.fasterxml.jackson.core:jackson-databind: affected >= 2.18.0, <= 2.18.8; >= 2.21.0, <= 2.21.4; fixed in 2.21.5, 2.18.9

## Suggested inspection (read-only)
- 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 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-mhm7-754m-9p8w (GitHub-reviewed advisory GHSA-mhm7-754m-9p8w lists affected ranges: Maven com.fasterxml.jackson.core:jackson-databind >=2.18.0 =2.21.0 <=2.21.4)

Commands are suggestions: review each one before running it.