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Standard
Vulnerability Identifier

CVE-2025-27533

2025-05-07
Severity Assessment
7.5
HIGH
CVSS v3.x Score
Clinical Analysis (Description)

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.

Vector Sequencing

Attack Parameters

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Impact Consequences

Technical Impact

Unchanged
Scope
None
Confidentiality
None
Integrity
High
Availability
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness Classification

CWE-CWE-789

Affected Population

Affected Configurations

Total: 30 detected entries

Software List Scrollable
ap
activemq
Vendor: apache • v5.16.5
ap
activemq
Vendor: apache • v6.1.0
ap
activemq
Vendor: apache • v5.16.4
ap
activemq
Vendor: apache • v5.18.1
ap
activemq
Vendor: apache • v5.16.1
ap
activemq
Vendor: apache • v5.16.3
ap
activemq
Vendor: apache • v6.1.1
ap
activemq
Vendor: apache • v5.17.5
ap
activemq
Vendor: apache • v5.18.3
ap
activemq
Vendor: apache • v6.1.4
ap
activemq
Vendor: apache • v6.1.5
ap
activemq
Vendor: apache • v5.16.6
ap
activemq
Vendor: apache • v5.18.0
ap
activemq
Vendor: apache • v6.1.3
ap
activemq
Vendor: apache • v5.17.2
ap
activemq
Vendor: apache • v5.17.0
ap
activemq
Vendor: apache • v5.18.4
ap
activemq
Vendor: apache • v5.17.4
ap
activemq
Vendor: apache • v6.1.2
ap
activemq
Vendor: apache • v5.16.2
ap
activemq
Vendor: apache • v6.0.0
ap
activemq
Vendor: apache • v5.17.6
ap
activemq
Vendor: apache • v5.16.0
ap
activemq
Vendor: apache • v5.17.3
ap
activemq
Vendor: apache • v5.18.2
ap
activemq
Vendor: apache • v5.18.5
ap
activemq
Vendor: apache • v5.16.7
ap
activemq
Vendor: apache • v5.17.1
ap
activemq
Vendor: apache • v5.18.6
ap
activemq
Vendor: apache • v6.0.1
Timeline

Time Line

PUBLICATION
07 May 2025
MODIFICATION
03 Nov 2025
FIRST PATCH
21 Oct 2025
Impact Statistics

Key Metrics

CVSS Score
7.5
HIGH
Products
30
Affected
Patches
2
Available
Public Exploit Available
Remediation Protocol

Recommended Solution

No automatic solution found. Check vendor references.
Recommended Actions for Administrators

Immediate Action Plan

1. Inventory

Identify all affected systems in your infrastructure.

2. Assessment

Assess exposure and criticality for your organization.

3. Mitigation

Apply patches or available workarounds.

4. Verification

Test and confirm effectiveness of applied measures.