Code Injection in com.cedarpolicy:cedar-java (CVE-2026-55771)
Summary
Code injection in com.cedarpolicy:cedar-java (CVE-2026-55771). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 4.9.0 or later.
Original description
The description as published by the source.
Summary
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.
Impact
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.
Impacted versions:
< 4.9
Patches
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.
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 cedar-policy-security@lists.cncf.io. Please do not create a public GitHub issue.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-55771 has been found in com.cedarpolicy:cedar-java.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade com.cedarpolicy:cedar-java to 4.9.0 or later.
If unsure, ask your IT team or search "com.cedarpolicy:cedar-java CVE-2026-55771" on the vendor's site.
CVE-2026-55771 (com.cedarpolicy:cedar-java) — CWE-94 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Patched: 4.9.0 — apply immediately
Workaround: Avoid relying on EntityIdentifier.equals() for security-sensitive comparisons until upgraded to version 4.9.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Arbitrary code execution (CWE-94) exists in com.cedarpolicy:cedar-java.
Check the vendor advisory for the affected versions of com.cedarpolicy:cedar-java.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to 4.9.0.
Workaround: Avoid relying on EntityIdentifier.equals() for security-sensitive comparisons until upgraded to version 4.9.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで com.cedarpolicy:cedar-java を使っているサービスとバージョンを洗い出す。
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2Apply temporary workaround mitigate
Avoid relying on `EntityIdentifier.equals()` for security-sensitive comparisons until upgraded to version `4.9`.パッチが適用されるまでの応急処置として、Avoid relying on
EntityIdentifier.equals()for security-sensitive comparisons until upgraded to version4.9. を実施。回避策の副作用 (機能低下) を確認した上で。 -
3Apply patch patch
Upgrade com.cedarpolicy:cedar-java to 4.9.0ステージング環境で 4.9.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com