RCE in Cedar-Policy Cedar-Java
CVE-2026-55773
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.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Cedar-Policy Cedar-Java — versions < 2.3.6, >= 3.1.2, < 3.4.1, >= 4.0.0, < 4.9.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-55773?
- CVE-2026-55773 is a high-severity vulnerability in Cedar-Policy Cedar-Java, classified under Code Injection. CVSS score: 8.8/10. Published 2026-07-13.
- How severe is CVE-2026-55773?
- High severity. CVSS v3 base score is 8.8 out of 10.