Vulnerability Description
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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Erlang | Erlang\/Inets | >= 5.10, < 9.1.0.5 |
| Erlang | Erlang\/Otp | >= 17.0, < 26.2.5.18 |
Related Weaknesses (CWE)
References
- https://cna.erlef.org/cves/CVE-2026-23941.htmlVendor Advisory
- https://github.com/erlang/otp/commit/a4b46336fd25aa100ac602eb9a627aaead7eda18Patch
- https://github.com/erlang/otp/commit/a761d391d8d08316cbd7d4a86733ba932b73c45bPatch
- https://github.com/erlang/otp/commit/e775a332f623851385ab6ddb866d9b150612ddf6Patch
- https://github.com/erlang/otp/security/advisories/GHSA-w4jc-9wpv-pqh7Vendor Advisory
- https://osv.dev/vulnerability/EEF-CVE-2026-23941Third Party Advisory
- https://www.erlang.org/doc/system/versions.html#order-of-versionsProduct
FAQ
What is CVE-2026-23941?
CVE-2026-23941 is a vulnerability with a CVSS score of 9.4 (CRITICAL). 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 f...
How severe is CVE-2026-23941?
CVE-2026-23941 has been rated CRITICAL with a CVSS base score of 9.4/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-23941?
Check the references section above for vendor advisories and patch information. Affected products include: Erlang Erlang\/Inets, Erlang Erlang\/Otp.