Apache Tomcat Rewrite rule bypass

Exploitation

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

CVSS 4.0

2.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U · score source

EPSS

• CVE-2025-31651: 4.26% estimated exploitation activity in the next 30 days; percentile 91.09 (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.

Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache Tomcat. For a subset of unlikely rewrite rule configurations, it was possible for a specially crafted request to bypass some rewrite rules. If those rewrite rules effectively enforced security constraints, those constraints could be bypassed. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.5, from 10.1.0-M1 through 10.1.39, from 9.0.0.M1 through 9.0.102. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 9.0.104, 10.1.40 or 11.0.6, which fix the issue.

Published by the source

28 Apr 2025, 21:30 UTC

Last modified by the source

3 Nov 2025, 22:57 UTC

Source last checked

26 Oct 2026, 16:40 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-ff77-26x5-69cr

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# Patch Next advisory brief: CVE-2025-31651

Advisory: Apache Tomcat Rewrite rule bypass
IDs: CVE-2025-31651, GHSA-ff77-26x5-69cr
Record: https://patchnext.com/advisories/cve-2025-31651 (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: Low (CVSS 2.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: org.apache.tomcat:tomcat-catalina 11.0.6, 10.1.40, 9.0.104; org.apache.tomcat.embed:tomcat-embed-core 11.0.6, 10.1.40, 9.0.104. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.tomcat:tomcat-catalina: affected >= 9.0.76, <= 9.0.102; >= 10.1.10, < 10.1.40; >= 11.0.0-M2, < 11.0.6; >= 8.5.0, <= 8.5.100; fixed in 9.0.104, 10.1.40, 11.0.6
- Maven org.apache.tomcat.embed:tomcat-embed-core: affected >= 9.0.76, <= 9.0.102; >= 10.1.10, < 10.1.40; >= 11.0.0-M2, < 11.0.6; >= 8.5.0, <= 8.5.100; fixed in 9.0.104, 10.1.40, 11.0.6

## Suggested inspection (read-only)
- Maven org.apache.tomcat:tomcat-catalina: check the installed version with your package manager.
- Maven org.apache.tomcat.embed:tomcat-embed-core: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.apache.tomcat:tomcat-catalina, org.apache.tomcat.embed:tomcat-embed-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-ff77-26x5-69cr (GitHub-reviewed advisory GHSA-ff77-26x5-69cr lists affected ranges: Maven org.apache.tomcat:tomcat-catalina >=9.0.76 =10.1.10 =11.0.0-M2 =8.5.0 =9.0.76 =10.1.10 =11.0.0-M2 =8.5.0 <=8.5.100)

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