Apache Software FoundationCVE-2026-77762
Apache Tomcat: race condition
High8.1CVE-2026-77762 · Published Sep 23, 2026 · updated Sep 30, 2026
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Apache Tomcat Product | >= 11.0.0-M1, <= 11.0.25 | No fix yet |
| >= 10.1.0-M1, <= 10.1.59 | No fix yet | |
| >= 9.0.39, <= 9.0.121 | No fix yet | |
| >= 8.5.59, <= 8.5.100 | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Severity from
- CISA (its enrichment of the CVE record)
- Weakness
- CWE-362
More Apache Software Foundation advisories
All Apache Software Foundation| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Sep 23 | Improper Check for Certificate Revocation vulnerability in Apache Tomcat | Medium6.5 | No fix yet |
| Sep 23 | Apache Tomcat: authentication bypass | Critical9.8 | No fix yet |
| Sep 23 | Apache Sling XSS: cross-site scripting | Medium6.1 | 2.4.12 |
| Sep 23 | Apache Sling XSS: cross-site scripting | Medium6.1 | 2.4.12 |
| Sep 23 | Apache Sling XSS: cross-site scripting | Medium6.1 | 2.4.12 |
| Sep 23 | Apache Sling XSS: cross-site scripting | Medium6.1 | 2.4.12 |