High 7.0Published Mar 13, 2026

CVE-2026-23941Request smuggling via first-wins Content-Length parsing in inets httpd

Updated under an hour ago (Oct 28, 2026, 5:50 AM ET)

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Exploited in the last 30 days

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 before OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to inets from 5.10 before 9.6.1, 9.3.2.3 and 9.1.0.5.

CVSS: 7.0 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:L
Weakness (CWE): CWE-444
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: EEF
NVD analysis: Modified
Record last updated: Jul 24, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Erlang OTP erlang:erlang/otp	from 5.10; fixed at 9.6.1, fixed at 9.3.2.3, fixed at 9.1.0.5	CNA record
erlang erlang/inets erlang:erlang/inets	from 5.10 before 9.1.0.5; from 9.3 before 9.3.2.3; from 9.6 before 9.6.1	NVD
erlang erlang/otp erlang:erlang/otp	from 17.0 before 26.2.5.18; from 27.0 before 27.3.4.9; from 28.0 before 28.4.1	NVD

References

References

https://github.com/erlang/otp/security/advisories/GHSA-w4jc-9wpv-pqh7	vendor-advisory, related
https://cna.erlef.org/cves/CVE-2026-23941.html	related, vendor-advisory
https://osv.dev/vulnerability/EEF-CVE-2026-23941	related, third-party-advisory
https://www.erlang.org/doc/system/versions.html#order-of-versions	x-version-scheme, product
https://github.com/erlang/otp/commit/a4b46336fd25aa100ac602eb9a627aaead7eda18	patch
https://github.com/erlang/otp/commit/a761d391d8d08316cbd7d4a86733ba932b73c45b	patch
https://github.com/erlang/otp/commit/e775a332f623851385ab6ddb866d9b150612ddf6	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.