CVE-2026-23941
CriticalSummary
The 'HTTP Request Smuggling' vulnerability in the Erlang OTP httpd module allows for inconsistent interpretation of HTTP headers. The server does not reject or normalize duplicate Content-Length headers, leading to desynchronization between the front-end and back-end.
Risk Assessment
An attacker could exploit this vulnerability to inject malicious data into the request queue, potentially leading to serious security breaches in the application. Organizations may be at risk of attacks that could include data theft or session hijacking.
Recommendation
It is recommended to upgrade to the latest version of Erlang OTP to mitigate this vulnerability. Additionally, configuring proxy servers to properly handle Content-Length headers is advisable.
Original NVD description (English source)
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in Erlang OTP (inets httpd module) allows HTTP Request Smuggling. This vulnerability is associated with program files lib/inets/src/http_server/httpd_request.erl and program routines httpd_request:parse_headers/7. The server does not reject or normalize duplicate Content-Length headers. The earliest Content-Length in the request is used for body parsing while common reverse proxies (nginx, Apache httpd, Envoy) honor the last Content-Length value. This violates RFC 9112 Section 6.3 and allows front-end/back-end desynchronization, leaving attacker-controlled bytes queued as the start of the next request. This issue affects OTP from OTP 17.0 until OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to inets from 5.10 until 9.6.1, 9.3.2.3 and 9.1.0.5.