CVE-2026-33930 Apache Traffic Server: Buffer overflow via Host field that has a long string value
An attacker can trigger a stack buffer overflow via a long Host header when redirect following is enabled, potentially leading to code execution or service disruption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-33930?
CVE-2026-33930 is a high-severity memory corruption 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 copies the client Host header into a fixed-size stack buffer without a bound during redirect handling, so an over-long Host header overflows the stack when redirect following is enabled.
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-121
Which versions are affected by CVE-2026-33930?
It affects 1 product.
Products include Apache Traffic Server.
How do I fix CVE-2026-33930?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-33930 being exploited?
There is no known exploitation of CVE-2026-33930 in the wild and no public exploit code.
Other vulnerabilities in Apache Traffic Server
Sources
Also known as DEBIAN-CVE-2026-33930, GHSA-4p58-9v5g-254v, UBUNTU-CVE-2026-33930.