CVE-2026-55771

Cedar-Java has policy injection, type confusion, and incorrect equality comparison vulnerabilities

CedarJava is an open source Java implementation of the Cedar policy language, used for fine-grained authorization decisions. Under certain circumstances, it could lead to incorrect equality comparisons.

Impacted versions:

< 4.9

Workarounds

Avoid relying on EntityIdentifier.equals() for security-sensitive comparisons until upgraded to version 4.9.

References

If you have any questions or comments about this advisory, Cedar asks that you contact us directly via email to [email protected]. Please do not create a public GitHub issue.

EntityIdentifier.equals() has inverted null/self branches

The EntityIdentifier.equals() method has inverted logic for null and self-reference checks, returning true for null comparisons and false for self-comparisons. This does not affect Cedar authorization decisions (computed in Rust from JSON), but could affect integrators who perform their own equality checks on entity identifiers.

Untrusted input is evaluated as executable code within the application's runtime environment. Typical impact: arbitrary code execution within the application's privilege context.

CVE-2026-55771 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.3.6, 3.4.1, 4.9.0); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

It has been addressed in CedarJava version 4.9 and above. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.

1. What is CVE-2026-55771? CVE-2026-55771 is a high-severity code injection vulnerability in com.cedarpolicy:cedar-java (maven), affecting versions < 2.3.6. It is fixed in 2.3.6, 3.4.1, 4.9.0. Untrusted input is evaluated as executable code within the application's runtime environment.
2. How severe is CVE-2026-55771? CVE-2026-55771 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of com.cedarpolicy:cedar-java are affected by CVE-2026-55771? com.cedarpolicy:cedar-java (maven) versions < 2.3.6 is affected.
4. Is there a fix for CVE-2026-55771? Yes. CVE-2026-55771 is fixed in 2.3.6, 3.4.1, 4.9.0. Upgrade to this version or later.
5. Is CVE-2026-55771 exploitable, and should I be worried? Whether CVE-2026-55771 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-55771 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-55771?
   • Upgrade com.cedarpolicy:cedar-java to 2.3.6 or later
   • Upgrade com.cedarpolicy:cedar-java to 3.4.1 or later
   • Upgrade com.cedarpolicy:cedar-java to 4.9.0 or later

Other vulnerabilities in com.cedarpolicy:cedar-java