Quick answers
- Is CVE-2026-111816 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-111816 being exploited in the wild.
- How severe is CVE-2026-111816?
- Critical severity, with a CVSS score of 9.3, published 21 October 2026.
- Which products and versions are affected?
- Apache Traffic Server 8.0.0–8.1.11, 9.0.0–9.2.15, 10.0.0–10.1.4, 10.2.0.
- Is there a fix for CVE-2026-111816?
- Yes: fixed in 9.2.16, 10.1.5, 10.2.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-111816 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-111816?
- Check whether you run Apache Traffic Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 9.2.16, 10.1.5, 10.2.1
Technical details
The vulnerability exists in Traffic Server's HTTP response parsing logic, where a Transfer-Encoding: chunked carve-out bypassed normal parse error rejection for malformed 302 responses. This allows responses that different HTTP peers interpret differently to be cached and served, enabling cache poisoning and HTTP response desynchronization attacks. The flaw affects multiple major versions and requires network access to exploit.
Affected products
- Apache Traffic Server 8.0.0–8.1.11, 9.0.0–9.2.15, 10.0.0–10.1.4, 10.2.0
Timeline
- 2026-10-21: disclosed