Vulnerability in Apache Software Foundation Apache Traffic Server

[ Description ]Official description

When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund21 Oct 2026WID-SEC-2026-4112

  Apache Traffic Server: Multiple vulnerabilities Translated from German

  Risk highCVE-2026-111814CVE-2026-111809CVE-2026-112381+12 more CVEs

[ References ]References

• lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc