CVE-2026-55772 json
CedarJava has a type confusion vulnerability
published 2026-06-19 4 mo ago modified 2026-10-24 15 d ago also GHSA-93g4-m6xv-cmvr , EUVD-2026-43522
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 41%
- public exploits
- 0
- none known
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 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 must reference that value in a when/unless clause. This vulnerability has been fixed in versions 2.3.6, 3.4.1, and 4.9.
Patch / fix
- maven com.cedarpolicy:cedar-java 2.3.6, 3.4.1, 4.9.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 3 mo ago
Exploit prediction
0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | com.cedarpolicy:cedar-java | <2.3.6 >=3.1.2, <3.4.1 >=4.0.0, <4.9.0 |
2.3.6 3.4.1 4.9.0 |
Affected products
- cedar-policy cedar-java
Classification
- Weakness
-
- CWE-843 Access of Resource Using Incompatible Type
References
Sources
- CVE List CVE-2026-55772
- GitHub Advisory GHSA-93g4-m6xv-cmvr
- NVD CVE-2026-55772
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