How severe is CVE-2011-4905?

No CVSS score has been assigned to CVE-2011-4905 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2011-4905?

CVE-2011-4905 affects the following packages: org.apache.activemq:activemq-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2011-4905?

Update org.apache.activemq:activemq-core to 5.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4905 is resolved across your whole dependency graph.

How do I detect CVE-2011-4905 in my Maven dependencies?

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

How do I mitigate CVE-2011-4905 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2011-4905 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2011-4905, including 1 in-the-wild exploitation 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-2011-4905?

CVE-2011-4905 has an EPSS (Exploit Prediction Scoring System) score of 8.5%, placing it in the 95th 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-2011-4905?

CVE-2011-4905 is classified as CWE-399 (CWE-399). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2011-4905 published, and has it been updated?

CVE-2011-4905 was published on January 5, 2012 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

CVE-2011-4905 — activemq-core

Fix: apache/activemq@3a71f8e

CVE-2011-4905 is a CWE-399 vulnerability in org.apache.activemq:activemq-core. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for org.apache.activemq:activemq-core — see the affected versions and patch details below.

Denial of Service in Apache ActiveMQ

Also known asGHSA-9wcx-326r-7j7w

Published

Jan 5, 2012

Updated

Apr 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

8.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs95th percentile — riskier than 95% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

☕org.apache.activemq:activemq-core

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 before 5.6.0 allows remote attackers to cause a denial of service (file-descriptor exhaustion and broker crash or hang) by sending many openwire failover:tcp:// connection requests.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.activemq:activemq-core`	all versions	5.6.0`org.apache.activemq:activemq-core:5.6.0`

Affected Products

1 product · 32 configurations

Application

activemqapache

≤ 5.5.1

29 versions

1.11.21.31.41.52.02.13.03.13.23.2.13.2.2

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 before 5.6.0 allows remote attackers to cause a denial o…

issues.apache.orgNVDJan 2012

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-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.activemq:activemq-core to 5.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2011-4905 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

Apache ActiveMQ before 5.6.0 allows remote attackers to cause a denial of service (file-descriptor exhaustion and broker crash or hang) by sending many openwire failover:tcp:// connection requests.