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ActivemqApplication · Apache

CVE-2025-27533

HIGH · 7.5 CVSS v3.1 Published 2025-05-07
Fix available
A fix is available. Upgrade to 5.16.8 / 5.17.7 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

During unmarshalling of OpenWire commands in Apache ActiveMQ, the size value of buffers is not properly validated, allowing an attacker to trigger excessive memory allocation by sending specially crafted commands with oversized size values, leading to memory exhaustion and denial of service.

MitigationUpgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7+, or 5.16.8, or implement mutual TLS as a compensating control to mitigate the risk on affected brokers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ActivemqApplication
Affected:>= 5.16.0, < 5.16.8>= 5.17.0, < 5.17.7>= 5.18.0, < 5.18.7>= 6.0.0, < 6.1.6

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify ActiveMQ installation and version
    Run 'activemq --version' or check the 'lib/activemq-boot.jar' or 'activemq-all.jar' version in the installation directory, or inspect the pom.xml if built from source
    Affected if The version falls within 5.16.0 to 5.16.7, 5.17.0 to 5.17.6, 5.18.0 to 5.18.6, or 6.0.0 to 6.1.5
  2. Confirm OpenWire protocol is enabled
    Check the ActiveMQ XML configuration file (typically conf/activemq.xml) for a transportConnector using the 'openwire' protocol, for example: <transportConnector name="openwire" uri="tcp://0.0.0.0:61616"/>
    Affected if An OpenWire transportConnector is defined and active, exposing port 61616 (or a custom OpenWire port)
  3. Verify the broker is network-exposed
    Review the bind address in the OpenWire transportConnector URI; if set to 0.0.0.0 or a public IP, the broker is externally reachable; check firewall rules and network ACLs for port 61616 (or custom port)
    Affected if The OpenWire port is accessible from untrusted networks or the internet, allowing remote attackers to send malicious commands

You are affected if you run an ActiveMQ version within the affected ranges AND have OpenWire enabled and network-accessible to untrusted parties.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.16.8 / 5.17.7 / 5.18.7 or later
Fixed in 5.16.85.17.75.18.7
Interim mitigation

Upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7+, or 5.16.8, or implement mutual TLS as a compensating control to mitigate the risk on affected brokers.

Recommended fix High confidence

Upgrade to 6.1.6+ (for 6.x users), 5.18.7+ (for 5.18.x users), 5.17.7+ (for 5.17.x users), or 5.16.8+ (for 5.16.x users). The 5.19.0+ releases also contain the fix.

  1. 1. Identify the current ActiveMQ version by checking the installation directory or running the broker version command
  2. 2. For version 5.16.x: upgrade to version 5.16.8 or later (5.18.7+ or 5.19.0+ recommended for longer support)
  3. 3. For version 5.17.x: upgrade to version 5.17.7 or later (5.18.7+ or 5.19.0+ recommended for longer support)
  4. 4. For version 5.18.x: upgrade to version 5.18.7 or later
  5. 5. For version 6.0.x to 6.1.5: upgrade to version 6.1.6 or later
  6. 6. Download the appropriate release from the Apache ActiveMQ downloads page (activemq.apache.org)
  7. 7. Stop the ActiveMQ broker cleanly
  8. 8. Back up the existing ActiveMQ data directory and configuration files
Caveat Review release notes for any breaking changes between versions. Mutual TLS is a configuration change that requires client-side certificate setup; ensure all clients are updated to present valid certificates before enforcing needClientAuth=true.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Activemq Scoped from the published advisory
  • Consultation6.0 h
  • Implementation10.0 h
  • Testing16.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,120
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-27533 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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