CVE-2026-73051 actix-http before 3.12.1 HTTP Request Smuggling via CL.TE
Attackers can smuggle HTTP requests via CL.TE desynchronization in actix-http, bypassing security controls and modifying backend data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73051?
CVE-2026-73051 is a medium-severity vulnerability in actix-http, published on 14 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
actix-http versions before 3.12.1 contain an HTTP request smuggling vulnerability in the HTTP/1.1 parser that accepts requests with both Content-Length and Transfer-Encoding: chunked headers. Unauthenticated remote attackers can exploit this through a front-end intermediary to desynchronize backend requests and smuggle malicious HTTP requests to the Actix service.
Weakness: CWE-444
Which versions are affected by CVE-2026-73051?
2 open source packages ship an affected version, including actix-http.
| Package | Affected | Fixed in |
|---|---|---|
actix-http crates.io | All versions | 3.12.1 |
actix-http crates.io | All versions | 3.12.1 |
How do I fix CVE-2026-73051?
Upgrade actix-http to 3.12.1 or later.
Is CVE-2026-73051 being exploited?
There is no known exploitation of CVE-2026-73051 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-73051, GHSA-rh8q-rpf9-79v6, GHSA-xhj4-vrgc-hr34, UBUNTU-CVE-2026-73051.