How severe is CVE-2026-46495?

No CVSS score has been assigned to CVE-2026-46495 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-46495?

CVE-2026-46495 affects the following packages: org.openidentityplatform.opendj:opendj-server-legacy (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-46495?

Update org.openidentityplatform.opendj:opendj-server-legacy to 5.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46495 is resolved across your whole dependency graph.

How do I detect CVE-2026-46495 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.openidentityplatform.opendj:opendj-server-legacy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-46495 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2026-46495 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-46495 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-46495?

CVE-2026-46495 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 66th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-46495?

CVE-2026-46495 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-46495 published, and has it been updated?

CVE-2026-46495 was published on September 15, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

Not in CISA KEV

CVE-2026-46495 — opendj-server-legacy

Fix: OpenIdentityPlatform/OpenDJ@7e3a759

CVE-2026-46495 is a Deserialization of Untrusted Data vulnerability in org.openidentityplatform.opendj:opendj-server-legacy. A fix is available for org.openidentityplatform.opendj:opendj-server-legacy — see the affected versions and patch details below.

OpenDJ Pre-Auth RCE via Java Deserialization in JMX RMI

Also known asGHSA-43x2-g84q-fmqx

Published

Sep 15, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-46495.

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs66th percentile — riskier than 66% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

☕org.openidentityplatform.opendj:opendj-server-legacy

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.openidentityplatform.opendj:opendj-server-legacy`	all versions	5.1.1`org.openidentityplatform.opendj:opendj-server-legacy:5.1.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.openidentityplatform.opendj:opendj-server-legacy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.openidentityplatform.opendj:opendj-server-legacy to 5.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46495 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

## 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 integrat