Apache Tomcat - HTTP/2 request headers not validated

Exploitation

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

CVSS

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

EPSS

• CVE-2026-41293: 1.70% estimated exploitation activity in the next 30 days; percentile 77.31 (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.

Versions Affected: Apache Tomcat 11.0.0-M1 to 11.0.21 Apache Tomcat 10.1.0-M1 to 10.1.54 Apache Tomcat 9.0.0.M1 to 9.0.117 Older, unsupported versions may also be affected Description: HTTP/2 request headers were not validated which may have triggered unexpected application behaviour if the application (quite reasonably) assumed that header value exposed through the Servlet API would be specification compliant. Mitigation: Users of the affected versions should apply one of the following mitigations: - Upgrade to Apache Tomcat 11.0.22 or later - Upgrade to Apache Tomcat 10.1.55 or later - Upgrade to Apache Tomcat 9.0.118 or later Credit: This issue was identified by Dawit Jeong (@dawitngoliath)

Published by the source

12 May 2026, 18:30 UTC

Last modified by the source

31 Aug 2026, 21:04 UTC

Source last checked

26 Oct 2026, 16:55 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-r29c-68gh-xp6x

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# Patch Next advisory brief: CVE-2026-41293

Advisory: Apache Tomcat - HTTP/2 request headers not validated
IDs: CVE-2026-41293, GHSA-r29c-68gh-xp6x
Record: https://patchnext.com/advisories/cve-2026-41293 (revision 1, source checked 26 Oct 2026, 16:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.apache.tomcat:tomcat-coyote 11.0.22, 10.1.55, 9.0.118; org.apache.tomcat.embed:tomcat-embed-core 11.0.22, 10.1.55, 9.0.118; org.apache.tomcat:tomcat 11.0.22, 10.1.55, 9.0.118. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.tomcat:tomcat-coyote: affected >= 8.5.0, < 9.0.118; >= 10.1.0-M1, < 10.1.55; >= 11.0.0-M1, < 11.0.22; fixed in 10.1.55, 9.0.118, 11.0.22
- Maven org.apache.tomcat.embed:tomcat-embed-core: affected >= 10.1.0-M1, < 10.1.55; >= 11.0.0-M1, < 11.0.22; >= 8.5.0, < 9.0.118; fixed in 10.1.55, 9.0.118, 11.0.22
- Maven org.apache.tomcat:tomcat: affected >= 10.1.0-M1, < 10.1.55; >= 11.0.0-M1, < 11.0.22; >= 8.5.0, < 9.0.118; fixed in 10.1.55, 9.0.118, 11.0.22

## Suggested inspection (read-only)
- Maven org.apache.tomcat:tomcat-coyote: check the installed version with your package manager.
- Maven org.apache.tomcat.embed:tomcat-embed-core: check the installed version with your package manager.
- Maven org.apache.tomcat:tomcat: 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.apache.tomcat:tomcat-coyote, org.apache.tomcat.embed:tomcat-embed-core, org.apache.tomcat:tomcat.
- 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-r29c-68gh-xp6x (GitHub-reviewed advisory GHSA-r29c-68gh-xp6x lists affected ranges: Maven org.apache.tomcat.embed:tomcat-embed-core >=10.1.0-M1 =11.0.0-M1 =8.5.0 =10.1.0-M1 =11.0.0-M1 =8.5.0 =8.5.0 =10.1.0-M1 =11.0.0-M1 <11.0.22)

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