CedarJava has a policy injection vulnerability
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-94.
Summary
CedarJava is an open source Java implementation of the Cedar policy language, used for fine-grained authorization decisions. In versions prior to 2.3.6, 3.4.1 and 4.9.0, under certain circumstances, improper input handling could allow 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. This vulnerability has been fixed in versions 2.3.6, 3.4.1, and 4.9.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| cedar-policy | cedar-java | before 2.3.6; 3.1.2 to before 3.4.1; 4.0.0 to before 4.9.0 | 2.3.6, 3.4.1, 4.9.0 | Patch available | CNA |
| — | com.cedarpolicy:cedar-java (Maven) | before 2.3.6 | 2.3.6 | Patch available | GHSA-qmch-v2q9-wg4p |
| — | com.cedarpolicy:cedar-java (Maven) | 3.1.2 to before 3.4.1 | 3.4.1 | Patch available | GHSA-qmch-v2q9-wg4p |
| — | com.cedarpolicy:cedar-java (Maven) | 4.0.0 to before 4.9.0 | 4.9.0 | Patch available | GHSA-qmch-v2q9-wg4p |
- cedar-java Vendorcedar-policy Affected before 2.3.6; 3.1.2 to before 3.4.1; 4.0.0 to before 4.9.0 Fixed in 2.3.6, 3.4.1, 4.9.0 Patch available CNA
- com.cedarpolicy:cedar-java (Maven) Vendor— Affected before 2.3.6 Fixed in 2.3.6 Patch available GHSA-qmch-v2q9-wg4p
- com.cedarpolicy:cedar-java (Maven) Vendor— Affected 3.1.2 to before 3.4.1 Fixed in 3.4.1 Patch available GHSA-qmch-v2q9-wg4p
- com.cedarpolicy:cedar-java (Maven) Vendor— Affected 4.0.0 to before 4.9.0 Fixed in 4.9.0 Patch available GHSA-qmch-v2q9-wg4p
Remediation
- Fix · CNA cedar-java (cedar-policy) Fixed in 2.3.6, 3.4.1, 4.9.0
- Fix · GHSA-qmch-v2q9-wg4p com.cedarpolicy:cedar-java (Maven) Fixed in 2.3.6 Advisory →
- Fix · GHSA-qmch-v2q9-wg4p com.cedarpolicy:cedar-java (Maven) Fixed in 3.4.1 Advisory →
- Fix · GHSA-qmch-v2q9-wg4p com.cedarpolicy:cedar-java (Maven) Fixed in 4.9.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55773
- 2026-10-03 Alias added: GHSA-qmch-v2q9-wg4p
References
More cedar-policy vulnerabilities
- TI-2026-40261 CedarJava has a type confusion vulnerability CVSS 3.1HIGH 8.8
- TI-2026-40260 CedarJava has policy injection, type confusion, and incorrect equality comparison vulnerabilities CVSS 3.1HIGH 8.8
- TI-2026-36628 @cedar-policy/authorization-for-expressjs has an authorization bypass via query string manipulation CVSS 3.1HIGH 8.8
Sources
- CVE-2026-55773 · CVE Program
- CVE-2026-55773 · NVD
- FIRST EPSS
- GHSA-qmch-v2q9-wg4p · GitHub Advisory Database · CC BY 4.0
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