Apache Tomcat - HTTP/2 request headers not validated
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)
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-41293US | — | Exploit | ||
Improper Input Validation vulnerability in Apache Tomcat.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.0.M1 through 9… | ||||
references
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2026/05/12/13WEB
- https://github.com/apache/tomcatPACKAGE
- https://github.com/apache/tomcat/commit/19f17a257797e8d139b33ff9c88d362a273be148WEB
- https://github.com/apache/tomcat/commit/1c70480466572c9192ed412ebefcd43fc63137fdWEB
- https://github.com/apache/tomcat/commit/2a2476460e823789f530a22207873ea8cd6eff3bWEB
- https://github.com/apache/tomcat/commit/3915fd27e6810b14ccd21e3d900bd8faef44d3dfWEB
- https://github.com/apache/tomcat/commit/57c2b3bfd62792631e1df24cf4237b990a0b36faWEB
- https://github.com/apache/tomcat/commit/c2925554c677da57390f940d856871e18daaacabWEB
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