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ActivemqApplication · Apache

CVE-2026-42253

MEDIUM · 6.1 CVSS v3.1 Published 2026-06-01
Fix available
A fix is available. Upgrade to 5.19.7 / 6.2.6 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache ActiveMQ, Apache ActiveMQ Web. The MessageServlet in the ActiveMQ web console API copies every JMS message property into an HTTP response header without any validation. This can allow overwriting and injecting security headers by setting them on JMS messages that are returned by the servlet. This issue affects Apache ActiveMQ: before 5.19.7, from 6.0.0 before 6.2.6; Apache ActiveMQ Web: before 5.19.7, from 6.0.0 before 6.2.6. Users are recommended to upgrade to version 5.19.7 or 6.2.6, which fixes the issue. The MessageServlet has now been deprecated and disabled by default.

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

The MessageServlet in Apache ActiveMQ web console copies JMS message properties into HTTP response headers without validation, allowing attackers to inject or overwrite security headers via specially crafted JMS messages. This XSS vulnerability stems from improper input neutralization.

MitigationUpgrade to Apache ActiveMQ version 5.19.7 or 6.2.6 which fixes the vulnerability and disables the vulnerable MessageServlet by default.

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:< 5.19.7>= 6.0.0, < 6.2.6
Activemq WebApplication
Affected:< 5.19.7>= 6.0.0, < 6.2.6

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

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

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 installed Apache ActiveMQ version
    Run 'activemq --version' or check the version file in the ActiveMQ installation directory (e.g., 'lib/activemq-core-*.jar' or 'VERSION' file in the root directory)
    Affected if Version is less than 5.19.7, or greater than or equal to 6.0.0 but less than 6.2.6
  2. Confirm Apache ActiveMQ Web console is enabled
    Check the ActiveMQ configuration (typically 'conf/jetty.xml' or 'conf/jetty-realm.properties') for web console servlet mappings; look for 'MessageServlet' or 'webconsole' entries
    Affected if Web console is enabled and accessible (by default on port 8161)
  3. Verify MessageServlet is active
    Inspect the web.xml in 'webapps/admin/WEB-INF/web.xml' or check jetty.xml for servlet definitions; look for 'MessageServlet' or '/api/message/*' endpoint mappings
    Affected if MessageServlet is explicitly enabled or mapped in the web console configuration
  4. Test for MessageServlet endpoint accessibility
    Attempt to access the web console at /api/message/* endpoints (e.g., http://localhost:8161/api/message) using curl or a browser; note this requires the console to be running
    Affected if The endpoint returns HTTP responses, indicating MessageServlet is actively handling requests

You are affected if your ActiveMQ version falls within the vulnerable range AND the MessageServlet in the web console is enabled and accessible.

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 5.19.7 / 6.2.6 or later
Fixed in 5.19.76.2.6
Interim mitigation

Upgrade to Apache ActiveMQ version 5.19.7 or 6.2.6 which fixes the vulnerability and disables the vulnerable MessageServlet by default.

Recommended fix High confidence

5.19.7 or 6.2.6 (depending on your major version branch)

  1. 1. Identify your current Apache ActiveMQ version by checking the installation directory or running the appropriate version command.
  2. 2. For ActiveMQ 5.x users: Upgrade to version 5.19.7 or later.
  3. 3. For ActiveMQ 6.x users: Upgrade to version 6.2.6 or later.
  4. 4. After upgrading, verify that the MessageServlet is disabled by default (it was deprecated and disabled as part of this fix).
  5. 5. If you were relying on the MessageServlet functionality, test your integration after the upgrade as you may need to explicitly enable it if still required, though this is not recommended due to the security implications.
Caveat The MessageServlet has been deprecated and disabled by default. If your application depends on this servlet, you will need to explicitly re-enable it (not recommended) or migrate to alternative functionality.

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

Fix this in Activemq Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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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-2026-42253 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data