Vulnerability · Published Oct 20, 2026 · Assigned by apache
CVE-2026-88041Apache Tomcat: HTTP/2 trailer header cross-contamination
High 7.5
In plain English
A high-severity security flaw in Apache Tomcat from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Incomplete cleanup vulnerability in Apache Tomcat allowed an trailer information from a previous request to leak into a subsequent request. This issue affects Apache Tomcat: from 11.0.0-M23 through 11.0.26, from 10.1.27 through 10.1.60, from 9.0.92 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fix the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | tomcat10 | no fix listed | DEBIAN-CVE-2026-88041 |
| Debian:13 | tomcat10 | no fix listed | DEBIAN-CVE-2026-88041 |
| Debian:14 | tomcat10 | no fix listed | DEBIAN-CVE-2026-88041 |
| Debian:13 | tomcat11 | no fix listed | DEBIAN-CVE-2026-88041 |
| Debian:14 | tomcat11 | no fix listed | DEBIAN-CVE-2026-88041 |
| Debian:12 | tomcat9 | 9.0.70-2 | DEBIAN-CVE-2026-88041 |
| Debian:13 | tomcat9 | 9.0.70-2 | DEBIAN-CVE-2026-88041 |
| Debian:14 | tomcat9 | 9.0.70-2 | DEBIAN-CVE-2026-88041 |
| Ubuntu:24.04:LTS | tomcat10 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:26.04:LTS | tomcat10 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:26.10 | tomcat10 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:26.04:LTS | tomcat11 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:26.10 | tomcat11 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:24.04:LTS | tomcat9 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:26.04:LTS | tomcat9 | no fix listed | UBUNTU-CVE-2026-88041 |
| Ubuntu:26.10 | tomcat9 | no fix listed | UBUNTU-CVE-2026-88041 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache Tomcat | 11.0.0-M23 – through 11.0.2610.1.27 – through 10.1.609.0.92 – through 9.0.122 |
Weakness: CWE-459 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N