Vulnerability in Apache Software Foundation Apache Traffic Server

[ Why it matters ]Priority signals

• Critical severity: CVSS 9.3

[ Description ]Official description

Apache Traffic Server forwarded a malformed 302 response that should have been rejected as a parse error, because the Transfer-Encoding: chunked carve-out bypassed the rejection path. A response that two peers can read differently is then stored and served, allowing cache poisoning and response-framing desync. 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