How severe is CVE-2026-33227?

CVE-2026-33227 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-33227?

CVE-2026-33227 affects the following packages: org.apache.activemq:activemq-client (Maven), org.apache.activemq:activemq-client (Maven), org.apache.activemq:activemq-broker (Maven), org.apache.activemq:activemq-broker (Maven), org.apache.activemq:activemq-all (Maven), org.apache.activemq:activemq-all (Maven), org.apache.activemq:activemq-web (Maven), org.apache.activemq:activemq-web (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-33227?

Update org.apache.activemq:activemq-client to 5.19.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33227 is resolved across your whole dependency graph.

How do I detect CVE-2026-33227 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-2026-33227 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-33227 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-33227 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-2026-33227?

CVE-2026-33227 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 37th 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-2026-33227?

CVE-2026-33227 is classified as Path Traversal (CWE-22). 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-2026-33227 published, and has it been updated?

CVE-2026-33227 was published on April 7, 2026 and was last updated on October 28, 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

MEDIUM severity

CVE-2026-33227 — activemq-client

MEDIUM

CVE-2026-33227 is a medium-severity (CVSS 4.3) Path Traversal vulnerability in org.apache.activemq:activemq-client. A fix is available for org.apache.activemq:activemq-client — see the affected versions and patch details below.

Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ: Improper Limitation of a Pathname to a Restricted Classpath Directory

Also known asBIT-activemq-2026-33227GHSA-h2h4-5m64-m273

Published

Apr 7, 2026

Updated

Oct 28, 2026

Affected

8 pkgs

Patched

8 / 8

Exploits

None indexed

Exploitation data as of Nov 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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-2026-33227.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.01%

Lower risk than most CVEs37th percentile — riskier than 37% 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

8 pkgs affected

☕org.apache.activemq:activemq-client☕org.apache.activemq:activemq-client☕org.apache.activemq:activemq-broker☕org.apache.activemq:activemq-broker☕org.apache.activemq:activemq-all☕org.apache.activemq:activemq-all☕org.apache.activemq:activemq-web☕org.apache.activemq:activemq-web

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

Improper validation and restriction of a classpath path name vulnerability in

Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ.

In two instances (when creating a Stomp consumer and also browsing messages in the Web console) an authenticated user provided "key" value could be constructed to traverse the classpath due to path concatenation. As a result, the application is exposed to a classpath path resource loading vulnerability that could potentially be chained together with another attack to lead to exploit.

This issue affects Apache ActiveMQ Client: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ Broker: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ All: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ Web: before 5.19.3, from 6.0.0 before 6.2.2; Apache ActiveMQ: before 5.19.3, from 6.0.0 before 6.2.2.

Users are recommended to upgrade to version 5.19.4 or 6.2.3, which fixes the issue. Note: 5.19.3 and 6.2.2 also fix this issue, but that is limited to non-Windows environments due to a path separator resolution bug fixed in 5.19.4 and 6.2.3.

Affected Packages

8 total 8 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.activemq:activemq-client`	all versions	5.19.3`org.apache.activemq:activemq-client:5.19.3`
☕Maven	`org.apache.activemq:activemq-client`	≥ 6.0.0&&< 6.2.2	6.2.2`org.apache.activemq:activemq-client:6.2.2`
☕Maven	`org.apache.activemq:activemq-broker`	all versions	5.19.3`org.apache.activemq:activemq-broker:5.19.3`
☕Maven	`org.apache.activemq:activemq-broker`	≥ 6.0.0&&< 6.2.2	6.2.2`org.apache.activemq:activemq-broker:6.2.2`
☕Maven	`org.apache.activemq:activemq-all`	all versions	5.19.3`org.apache.activemq:activemq-all:5.19.3`
☕Maven	`org.apache.activemq:activemq-all`	≥ 6.0.0&&< 6.2.2	6.2.2`org.apache.activemq:activemq-all:6.2.2`

Affected Products

3 products · 6 configurations

Application

activemqapache

≥ 6.0.0 && < 6.2.2

range

Application

activemq brokerapache

≥ 6.0.0 && < 6.2.2

range

Application

activemq webapache

≥ 6.0.0 && < 6.2.2

range

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 5.19.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33227 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

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

To exploit this issue, an attacker must have valid credentials to create a Stomp consumer or log into the Web console. Additionally, this flaw only allows an authenticated user to read files from the classpath of the application, there is no impact to the availability or the integrity of the application. Due to these…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for CVE-2026-33227 (CC BY 4.0)

Frequently Asked Questions

Improper validation and restriction of a classpath path name vulnerability in Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ. In two instances (when creating a Stomp consumer and also browsing messages in the Web console) an authenticated user provided "key" value could be constructed to traverse the classpath due to path concatenation. As a result, the application is exposed to a classpath path resource loading vulnerability that could potentially be chained together with another attack to lead to exploit. This issue affect

O3 Security · Impact-Aware SCA

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Find it across Maven, including transitive dependencies.

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CVSS Score

4.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CWE Classification

CWE-22Path Traversal

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

activemq

6.9/10

Code-Review10/10

Maintained10/10

Branch-ProtectionN/A

Assessed Nov 9, 2026

Timeline

Disclosed

Apr 7, 2026

Last updated

Oct 28, 2026

Identifiers

CVE-2026-33227

GHSA-h2h4-5m64-m273

BIT-activemq-2026-33227

References

Advisoryactivemq.apache.org · CVE 2026 33227 announcement.txt Advisorygithub.com · CVE 2026 33227.json Advisorynvd.nist.gov · CVE 2026 33227 Webopenwall.com Webrepo.maven.apache.org · maven2 Packagegithub.com · activemq

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting activemq-client are rated as high or higher (top: critical).

CVE-2026-50734CVE-2026-53917CVE-2026-39304CVE-2025-27533CVE-2023-46604CVE-2013-1879CVE-2013-3060CVE-2015-1830

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 28, 2026

CVE-2026-33227 — activemq-client

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2026-33227 in your dependencies?