CedarJava has type confusion vulnerability

Exploitation

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

CVSS

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

EPSS

• CVE-2026-55772: 0.48% estimated exploitation activity in the next 30 days; percentile 41.41 (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 CedarJava is an open source Java implementation of the Cedar policy language, used for fine-grained authorization decisions. Under certain circumstances, improper input handling could allow type confusion across the Java-Rust FFI boundary. Impact Record-to-Entity type confusion across the Java-Rust FFI boundary CedarJava sends authorization requests to the Rust cedar-policy evaluator as JSON. The JSON protocol reserves magic single-key object shapes (entity and extn) for entity references and extension values. When serializing a CedarMap, there is no validation preventing these reserved keys from being used. If an integrating service builds a CedarMap from caller-supplied key/value data (such as request headers, user-defined metadata, or resource tags), an actor who controls those keys could cause the Rust evaluator to interpret a record as an entity reference. This issue requires the integrating service to build a CedarMap where the an actor controls the keys, and a policy…

Published by the source

19 Jun 2026, 14:38 UTC

Last modified by the source

28 Jul 2026, 01:55 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-93g4-m6xv-cmvr

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# Patch Next advisory brief: CVE-2026-55772

Advisory: CedarJava has type confusion vulnerability
IDs: CVE-2026-55772, GHSA-93g4-m6xv-cmvr
Record: https://patchnext.com/advisories/cve-2026-55772 (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: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: com.cedarpolicy:cedar-java 4.9.0, 3.4.1, 2.3.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven com.cedarpolicy:cedar-java: affected < 2.3.6; >= 3.1.2, < 3.4.1; >= 4.0.0, < 4.9.0; fixed in 4.9.0, 3.4.1, 2.3.6

## Suggested inspection (read-only)
- Maven com.cedarpolicy:cedar-java: 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.cedarpolicy:cedar-java.
- 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-93g4-m6xv-cmvr (GitHub-reviewed advisory GHSA-93g4-m6xv-cmvr lists affected ranges: Maven com.cedarpolicy:cedar-java >=0 =3.1.2 =4.0.0 <4.9.0)

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