CVE-2026-73812 inets, httpd: HTTP Request Smuggling via Transfer-Encoding and Content-Length
Attackers can exploit HTTP request smuggling in Erlang OTP inets by sending conflicting Transfer-Encoding and Content-Length headers, bypassing front-end security controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73812?
CVE-2026-73812 is a high-severity vulnerability in Erlang OTP, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
httpd function check_header/3 rejects duplicate Content-Length (per CVE-2026-23941) but never checks for the TE+CL co-presence that RFC 9112 §6.3 identifies as a probable smuggling attempt. handle_body/3 frames by chunked and silently discards Content-Length. A CL-preferring front-end paired with chunked-preferring inets creates a classic CL.TE front-end/back-end desync.
This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
Weakness: CWE-444
Which versions are affected by CVE-2026-73812?
How do I fix CVE-2026-73812?
Upgrade to a fixed version.
Is CVE-2026-73812 being exploited?
There is no known exploitation of CVE-2026-73812 in the wild and no public exploit code.
Sources
Also known as AZL-98490, DEBIAN-CVE-2026-73812, EEF-CVE-2026-73812, GHSA-7j6m-4ffg-hg46, UBUNTU-CVE-2026-73812.