How severe is CVE-2015-5254?

CVE-2015-5254 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2015-5254?

CVE-2015-5254 affects the following packages: org.apache.activemq:activemq-client (Maven), org.apache.activemq:activemq-client (Maven). Ecosystems affected: Maven.

How do I fix CVE-2015-5254?

Update org.apache.activemq:activemq-client to 5.11.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-5254 is resolved across your whole dependency graph.

How do I detect CVE-2015-5254 in my Maven dependencies?

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

How do I mitigate CVE-2015-5254 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2015-5254 actively exploited in the wild?

Yes. There are 6 known exploit references for CVE-2015-5254, including 3 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2015-5254?

CVE-2015-5254 has an EPSS (Exploit Prediction Scoring System) score of 38.2%, placing it in the 99th 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 warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2015-5254?

CVE-2015-5254 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2015-5254 published, and has it been updated?

CVE-2015-5254 was published on January 8, 2016 and was last updated on April 10, 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

CRITICAL severity

CVE-2015-5254 — activemq-client

CRITICALFix: apache/activemq@6f03921

CVE-2015-5254 is a critical-severity (CVSS 9.8) Improper Input Validation vulnerability in org.apache.activemq:activemq-client. 6 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for org.apache.activemq:activemq-client — see the affected versions and patch details below.

Improper Input Validation in Apache ActiveMQ

Also known asGHSA-q9hr-3pg4-3jp4

Published

Jan 8, 2016

Updated

Apr 10, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

6 known

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

38.2%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

☕org.apache.activemq:activemq-client☕org.apache.activemq:activemq-client

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

Apache ActiveMQ 5.x before 5.13.0 does not restrict the classes that can be serialized in the broker, which allows remote attackers to execute arbitrary code via a crafted serialized Java Message Service (JMS) ObjectMessage object.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.activemq:activemq-client`	≥ 5.0.0&&< 5.11.3	5.11.3`org.apache.activemq:activemq-client:5.11.3`
☕Maven	`org.apache.activemq:activemq-client`	≥ 5.12.0&&< 5.12.2	5.12.2`org.apache.activemq:activemq-client:5.12.2`

Affected Products

3 products · 27 configurations

Application

activemqapache

24 versions

5.0.05.1.05.2.05.3.05.3.15.3.25.4.05.4.15.4.35.5.05.5.15.6.0

fedorafedoraproject

2 versions

2223

Application

openshiftredhat

1 version

2.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Apache ActiveMQ 5.x before 5.13.0 does not restrict the classes that can…

github.comAwesomePocJun 2020

Report on github.com

github.comGithubAug 2019

Report on github.com

github.comGithubAug 2020

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.activemq:activemq-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.activemq:activemq-client to 5.11.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-5254 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

A malicious message producer needs to authenticate to EAP in order to send messages. Also, the use of JMS ObjectMessage needs to be chosen by the developer of the application. Therefore this issue is rated as moderate.

Workaround published by Red Hat

If you do deploy a JMS publisher, and subscriber, and don't trust the messages sent to you by your clients, you could mitigate this issue by installing a Java agent which restricts the classes which can be deserialized. This is an article with the recommended approach: https://access.redhat.com/solutions/2190911 You could also mitigate this issue using the features of the Java Virtual Machine added in JEP 290: http://openjdk.java.net/jeps/290

Source: Red Hat security advisory for CVE-2015-5254 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat JBoss A-MQ 6.3	see advisory	RHSA-2016:2036
Red Hat JBoss Fuse 6.3	see advisory	RHSA-2016:2035
Red Hat OpenShift Enterprise 2.2	`activemq-0:5.9.0-6.redhat.611454.el6op`	RHSA-2016:0489

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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