Which versions of Activemq are affected by CVE-2025-27533?

CVE-2025-27533 presents notable security risk rated CVSS 6.9. Exploitation could compromise the security of affected deployments. Proof-of-concept code is publicly available.. A patch is available.

Is there a public PoC exploit available for CVE-2025-27533?

Yes, a public proof-of-concept exploit is available for CVE-2025-27533. Prioritise patching immediately. EPSS: 2.3%.

How to fix or mitigate CVE-2025-27533?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Activemq CVE-2025-27533

Q: What is the CVSS score of CVE-2025-27533?

CVE-2025-27533 has a CVSS 4.0 base score of 6.9 (Medium). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:D/RE:M/U:Red. EPSS exploitation probability: 2.3%.

MEDIUM

Memory Allocation with Excessive Size Value (CWE-789)

2025-05-07 security@apache.org

Apache Denial Of Service Activemq Red Hat

6.9

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

6.9 MEDIUM

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:D/RE:M/U:Red

Red Hat

4.9 MEDIUM

qualitative

Primary rating from NVD.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:D/RE:M/U:Red

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 18:40 vuln.today

PoC Detected

Nov 03, 2025 - 20:18 vuln.today

Public exploit code

CVE Published

May 07, 2025 - 09:15 nvd

MEDIUM 6.9

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

81 maven packages depend on org.apache.activemq:activemq-client (8 direct, 73 indirect)
72 maven packages depend on org.apache.activemq:activemq-openwire-legacy (3 direct, 69 indirect)

Ecosystem-wide dependent count for version 5.17.0 and other introduced versions.

DescriptionCVE.org

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ.

During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected.

Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue.

Existing users may implement mutual TLS to mitigate the risk on affected brokers.

AnalysisAI

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-789. Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ. During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected. Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue. Existing users may implement mutual TLS to mitigate the risk on affected brokers. Affected products include: Apache Activemq. Version information: before 6.1.6.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.