CVE-2026-55771: Cedar java Cedar-Java Has Policy Injection, Type Vulnerability

HIGH
Advisory Identifier: GHSA-4r9r-4425-74p7
CVSS 8.8
CWE-94 CWE-843 CWE-697
Published
Advisory Summary

CVE-2026-55771 is a HIGH (CVSS 8.8) cedar-java has policy injection, type vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Cedar java libraries in the Maven ecosystem. The issue involves cedar-java has policy injection, type confusion, and incorrect equality comparison vulnerabilities. Remediation is available by upgrading affected packages to version 2.3.6, 3.4.1, 4.9.0.

CVE-2026-55771 at a Glance

CVE Identifier CVE-2026-55771
GHSA Identifier GHSA-4r9r-4425-74p7
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Cedar java
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-55771

To remediate this vulnerability, upgrade all affected Cedar java dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

com.cedarpolicy:cedar-java fixed: 2.3.6
<dependency>
    <groupId>com.cedarpolicy</groupId>
    <artifactId>cedar-java</artifactId>
    <version>2.3.6</version>
</dependency>
com.cedarpolicy:cedar-java fixed: 3.4.1
<dependency>
    <groupId>com.cedarpolicy</groupId>
    <artifactId>cedar-java</artifactId>
    <version>3.4.1</version>
</dependency>
com.cedarpolicy:cedar-java fixed: 4.9.0
<dependency>
    <groupId>com.cedarpolicy</groupId>
    <artifactId>cedar-java</artifactId>
    <version>4.9.0</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

mvn dependency:tree -Dincludes=com.cedarpolicy

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-55771, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.cedarpolicy

Analyze the terminal output to locate any version of Cedar java in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.3.6), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.cedarpolicy command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. In Cedar java, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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](mailto:cedar-policy-security@lists.cncf.io). Please do not create a public GitHub issue.

CVE-2026-55771 Affected Cedar java Versions

3 component(s)
Fixed Versions:
2.3.63.4.14.9.0
Product / Package Ecosystem Affected Versions Fixed Version
com.cedarpolicy:cedar-java
Maven
< 2.3.6
2.3.6
com.cedarpolicy:cedar-java
Maven
≥ 3.1.2
< 3.4.1
3.4.1
com.cedarpolicy:cedar-java
Maven
≥ 4.0.0
< 4.9.0
4.9.0

References

Frequently Asked Questions

What is CVE-2026-55771?
CVE-2026-55771 is a security vulnerability in Cedar java involving Cedar-Java has policy injection, type confusion, and incorrect equality comparison vulnerabilities under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Cedar java versions are affected?
Affected versions include releases prior to 2.3.6, 3.4.1, 4.9.0 across affected packages: com.cedarpolicy:cedar-java.
What version fixes CVE-2026-55771?
Upgrading to 2.3.6, 3.4.1, 4.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is cedar-java affected?
Yes, com.cedarpolicy:cedar-java is affected in releases prior to 2.3.6, 3.4.1, 4.9.0. Upgrade your dependency to 2.3.6, 3.4.1, 4.9.0 or later.
What is the CVSS score of CVE-2026-55771?
CVE-2026-55771 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-55771?
CVE-2026-55771 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check Maven dependencies for CVE-2026-55771?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.cedarpolicy'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4r9r-4425-74p7",
  "modified" : "2026-07-28T14:50:25Z",
  "published" : "2026-07-28T14:50:25Z",
  "aliases" : [ "CVE-2026-55771" ],
  "summary" : "Cedar-Java has policy injection, type confusion, and incorrect equality comparison vulnerabilities",
  "details" : "### Summary\n\nCedarJava 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.\n\n### Impact\n\n**`EntityIdentifier.equals()` has inverted null/self branches**\n\nThe `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.\n\n### Impacted versions: \n< 4.9\n\n### Patches\nIt 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.\n\n### Workarounds\nAvoid relying on `EntityIdentifier.equals()` for security-sensitive comparisons until upgraded to version `4.9`.\n\n### References\nIf 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](mailto:cedar-policy-security@lists.cncf.io). Please do not create a public GitHub issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.cedarpolicy:cedar-java"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.3.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.cedarpolicy:cedar-java"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.1.2"
      }, {
        "fixed" : "3.4.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.cedarpolicy:cedar-java"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.9.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cedar-policy/cedar-java/security/advisories/GHSA-4r9r-4425-74p7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-55771"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cedar-policy/cedar-java"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-697", "CWE-843", "CWE-94" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-28T14:50:25Z",
    "nvd_published_at" : "2026-07-13T20:16:48Z"
  }
}