CVE-2026-58155 Apache Traffic Server: Header-name length truncation enables header aliasing and request smuggling
Attackers can bypass security policies and smuggle requests by exploiting header name truncation in Apache Traffic Server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-58155?
CVE-2026-58155 is a critical vulnerability in Apache Traffic Server, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Apache Traffic Server truncates over-long header names, allowing header aliasing, request smuggling, and policy bypass.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3.
Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.
Weakness: CWE-444
Which versions are affected by CVE-2026-58155?
It affects 1 product.
Products include Apache Traffic Server.
How do I fix CVE-2026-58155?
Upgrade to a fixed version.
Is CVE-2026-58155 being exploited?
There is no known exploitation of CVE-2026-58155 in the wild and no public exploit code.
Other vulnerabilities in Apache Traffic Server
Sources
Also known as DEBIAN-CVE-2026-58155, GHSA-9jfm-2xhc-ghxj, UBUNTU-CVE-2026-58155.