Vulnerability · Published Sep 1, 2026 · Assigned by EEF
CVE-2026-73812inets, httpd: HTTP Request Smuggling via Transfer-Encoding and Content-Length
High 8.3
In plain English
A high-severity security flaw in OTP from Erlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | erlang | no fix listed | DEBIAN-CVE-2026-73812 |
| Debian:13 | erlang | 1:27.3.4.1+dfsg-1+deb13u4 | DEBIAN-CVE-2026-73812 |
| Debian:14 | erlang | 1:29.0.6+dfsg-1 | DEBIAN-CVE-2026-73812 |
| Ubuntu:22.04:LTS | erlang | 1:24.2.1+dfsg-1ubuntu0.7 | UBUNTU-CVE-2026-73812 |
| Ubuntu:22.04:LTS | erlang | 1:24.2.1+dfsg-1ubuntu0.7 | USN-8827-1 |
| Ubuntu:24.04:LTS | erlang | 1:25.3.2.8+dfsg-1ubuntu4.7 | USN-8827-1 |
| Ubuntu:24.04:LTS | erlang | 1:25.3.2.8+dfsg-1ubuntu4.7 | UBUNTU-CVE-2026-73812 |
| Ubuntu:26.04:LTS | erlang | 1:27.3.4.6+dfsg-1ubuntu0.1 | USN-8827-1 |
| Ubuntu:26.04:LTS | erlang | 1:27.3.4.6+dfsg-1ubuntu0.1 | UBUNTU-CVE-2026-73812 |
Affected products (as reported)
Weakness: CWE-444 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N