CVE-2025-31699 Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2025-31699?
CVE-2025-31699 is a critical vulnerability in Apache Traffic Server, published on 21 Oct 2026.
Official description
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
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.
Weakness: CWE-444
Which versions are affected by CVE-2025-31699?
How do I fix CVE-2025-31699?
No fix has been published for CVE-2025-31699 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-31699 being exploited?
There is no known exploitation of CVE-2025-31699 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2025-31699, GHSA-4h97-h3mf-j6w7, UBUNTU-CVE-2025-31699.