CVE-2026-55773 — cedar-java
HIGHCVE-2026-55773 is a high-severity (CVSS 8.8) Code Injection vulnerability in com.cedarpolicy:cedar-java. A fix is available for com.cedarpolicy:cedar-java — see the affected versions and patch details below.
CedarJava has a policy injection vulnerability
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-55773 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
com.cedarpolicy:cedar-java☕com.cedarpolicy:cedar-java☕com.cedarpolicy:cedar-javaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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 policy injection.
Impact
Cedar-expression injection via unescaped toCedarExpr()
The toCedarExpr() method on Cedar Value types does not escape special characters (" or \) when converting values to Cedar source code. If an integrator uses toCedarExpr() to build policy text at runtime from user-controlled values, an actor could inject arbitrary Cedar expressions. For example, injecting || true into a permit ... when { ... } clause could make the permit unconditional, or injecting && false into a forbid clause could prevent the forbid from triggering.
This issue requires the integrator to use toCedarExpr() to build policy text at runtime from user-controlled input.
Impacted versions:
< 4.9
Patches
Addressed in CedarJava version 2.3.6, 3.4.1, and 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.
Workarounds
Validate and sanitize all user-supplied input before passing it to toCedarExpr(). Avoid building policy text at runtime from user-controlled values.
References
If you have any questions or comments about this advisory, we ask that you contact us directly via email to [email protected]. Please do not create a public GitHub issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.cedarpolicy:cedar-java | all versions | 2.3.6com.cedarpolicy:cedar-java:2.3.6 |
| ☕Maven | com.cedarpolicy:cedar-java | ≥ 3.1.2&&< 3.4.1 | 3.4.1com.cedarpolicy:cedar-java:3.4.1 |
| ☕Maven | com.cedarpolicy:cedar-java | ≥ 4.0.0&&< 4.9.0 | 4.9.0com.cedarpolicy:cedar-java:4.9.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.cedarpolicy:cedar-java, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.cedarpolicy:cedar-java to 2.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55773 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-55773 in your dependencies?
Find it across Maven, including transitive dependencies.