CVE-2026-46495: Opendj server legacy Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-43x2-g84q-fmqx
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CWE-502
Published
Advisory Summary

CVE-2026-46495 is a CRITICAL remote code execution vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Opendj server legacy libraries in the Maven ecosystem. The issue involves opendj pre-auth rce via java deserialization in jmx rmi. Remediation is available by upgrading affected packages to version 5.1.1.

CVE-2026-46495 at a Glance

CVE Identifier CVE-2026-46495
GHSA Identifier GHSA-43x2-g84q-fmqx
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Opendj server legacy
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-46495

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

org.openidentityplatform.opendj:opendj-server-legacy fixed: 5.1.1 
<dependency>
    <groupId>org.openidentityplatform.opendj</groupId>
    <artifactId>opendj-server-legacy</artifactId>
    <version>5.1.1</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=org.openidentityplatform.opendj

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-46495, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.openidentityplatform.opendj

Analyze the terminal output to locate any version of Opendj server legacy in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.1.1), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.openidentityplatform.opendj 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-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Opendj server legacy, 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 **Description** A Deserialization of Untrusted Data (CWE-502) issue in OpenDJ's JMX RMI connector allows an unauthenticated remote attacker to deserialize arbitrary Java objects on the server. The vulnerability exists because the platform reads and processes attacker-controlled bytes prior to authentication. This affects OpenDJ Community Edition through 5.1.0. This has been patched in version 5.1.1. ## Impact This impacts all current OpenDJ releases where the JMX Connection Handler is enabled. While disabled by default, it is frequently enabled in practice for monitoring integrations. Exploitation requires TCP reachability to the configured listener and does not require authentication, prior privileges, or client certificates. Successful exploitation results in unauthenticated Remote Code Execution (RCE), with the severity depending on the runtime classpath and Java version. Unauthenticated RCE was demonstrated on the OpenDJ 4.4.15 (JDK 11 + Jackson 2.12.6.1). ## Patch This has been patched in OpenDJ Community Edition version 5.1.1. Users are encouraged to update to the latest release.

CVE-2026-46495 Affected Opendj server legacy Versions

1 component(s)
Fixed Versions:
5.1.1
Product / Package Ecosystem Affected Versions Fixed Version
org.openidentityplatform.opendj:opendj-server-legacy
maven/org.openidentityplatform.opendj/opendj-server-legacy
Maven
< 5.1.1
5.1.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/OpenIdentityPlatform/OpenDJ/security/advisories/GHSA-43x2-g84q-fmqx
Opendj server legacy Source Repository REPOSITORY
https://github.com/OpenIdentityPlatform/OpenDJ

Frequently Asked Questions

What is CVE-2026-46495?
CVE-2026-46495 is a security vulnerability in Opendj server legacy involving OpenDJ Pre-Auth RCE via Java Deserialization in JMX RMI under CWE-502: Deserialization of Untrusted Data.
Which Opendj server legacy versions are affected?
Affected versions include releases prior to 5.1.1 across affected packages: org.openidentityplatform.opendj:opendj-server-legacy.
What version fixes CVE-2026-46495?
Upgrading to 5.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is opendj-server-legacy affected?
Yes, org.openidentityplatform.opendj:opendj-server-legacy is affected in releases prior to 5.1.1. Upgrade your dependency to 5.1.1 or later.
What CWE is associated with CVE-2026-46495?
CVE-2026-46495 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check Maven dependencies for CVE-2026-46495?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.openidentityplatform.opendj'. 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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-43x2-g84q-fmqx",
  "modified" : "2026-06-22T21:10:31Z",
  "published" : "2026-06-22T21:10:31Z",
  "aliases" : [ "CVE-2026-46495" ],
  "summary" : "OpenDJ Pre-Auth RCE via Java Deserialization in JMX RMI",
  "details" : "## Summary\n\n**Description**\n\nA Deserialization of Untrusted Data (CWE-502) issue in OpenDJ's JMX RMI connector allows an unauthenticated remote attacker to deserialize arbitrary Java objects on the server. The vulnerability exists because the platform reads and processes attacker-controlled bytes prior to authentication. This affects OpenDJ Community Edition through 5.1.0. This has been patched in version 5.1.1.\n\n## Impact\nThis impacts all current OpenDJ releases where the JMX Connection Handler is enabled. While disabled by default, it is frequently enabled in practice for monitoring integrations. Exploitation requires TCP reachability to the configured listener and does not require authentication, prior privileges, or client certificates. Successful exploitation results in unauthenticated Remote Code Execution (RCE), with the severity depending on the runtime classpath and Java version. Unauthenticated RCE was demonstrated on the OpenDJ 4.4.15 (JDK 11 + Jackson 2.12.6.1).\n\n## Patch\nThis has been patched in OpenDJ Community Edition version 5.1.1. Users are encouraged to update to the latest release.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.openidentityplatform.opendj:opendj-server-legacy"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.1.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.1.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/OpenIdentityPlatform/OpenDJ/security/advisories/GHSA-43x2-g84q-fmqx"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/OpenIdentityPlatform/OpenDJ"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-22T21:10:31Z",
    "nvd_published_at" : null
  }
}