Jenkins has a log message injection vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2025-59476: 0.38% estimated exploitation activity in the next 30 days; percentile 32.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

In Jenkins 2.527 and earlier, LTS 2.516.2 and earlier, the log formatter that prepares log messages for console output (including jenkins.log and equivalent) does not restrict or transform the characters that can be inserted from user-specified content in log messages. This allows attackers able to control log message contents to insert line break characters, followed by forged log messages that may mislead administrators reviewing log output. Jenkins 2.528, LTS 2.516.3 adds an indicator at the beginning of a line that was inserted as part of log message content: [CR], [LF], or [CRLF] (representing the kind of line break), followed by .

Published by the source

17 Sep 2025, 15:30 UTC

Last modified by the source

5 Nov 2025, 20:45 UTC

Source last checked

26 Oct 2026, 16:40 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qrh5-jg98-cr48

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# Patch Next advisory brief: CVE-2025-59476

Advisory: Jenkins has a log message injection vulnerability
IDs: CVE-2025-59476, GHSA-qrh5-jg98-cr48
Record: https://patchnext.com/advisories/cve-2025-59476 (revision 1, source checked 26 Oct 2026, 16:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.jenkins-ci.main:jenkins-core 2.528, 2.516.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.jenkins-ci.main:jenkins-core: affected < 2.516.3; >= 2.517, < 2.528; fixed in 2.528, 2.516.3

## Suggested inspection (read-only)
- Maven org.jenkins-ci.main:jenkins-core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.jenkins-ci.main:jenkins-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-qrh5-jg98-cr48 (GitHub-reviewed advisory GHSA-qrh5-jg98-cr48 lists affected ranges: Maven org.jenkins-ci.main:jenkins-core >=0 =2.517 <2.528)

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