Cache Poisoning Vulnerability in Apache Traffic Server Software
CVE-2026-111816

9.2CRITICAL

Key Information:

Vendor

Apache
Status
Apache Traffic Server
Vendor
CVE Published:
21 October 2026

What is CVE-2026-111816?

A vulnerability in Apache Traffic Server allows the proper forwarding of a malformed 302 response due to a bypass in the Transfer-Encoding: chunked rule. This misconfiguration results in different reads by two peers and enables an attacker to exploit cache mechanisms, leading to potential cache poisoning and response framing misalignments. Upgrading to versions 9.2.16, 10.1.5, or 10.2.1 is strongly recommended to mitigate this issue.

Affected Version(s)

Apache Traffic Server 8.0.0 <= 8.1.11

Apache Traffic Server 9.0.0 <= 9.2.15

Apache Traffic Server 10.0.0 <= 10.1.4

References

https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb1...
vendor-advisory

CVSS V4

Score:
9.2
Severity:
CRITICAL
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Apache Community
OneZ3r0
.