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TI-2026-19284 Aliases CVE-2026-23941

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

Priority LOW 31CWE-444Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00481 41st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ErlangOTP5.10 and later—No fix listedCNA
ErlangOTP17.0 and later—No fix listedCNA
  • OTP VendorErlang Affected 5.10 and later Fixed in — No fix listed CNA
  • OTP VendorErlang Affected 17.0 and later Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:erlang:erlang\/inets:*:*:*:*:*:*:*:*5.10 to before 9.1.0.5; 9.3 to before 9.3.2.3; 9.6 to before 9.6.1VulnerableErlang
cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*17.0 to before 26.2.5.18; 27.0 to before 27.3.4.9; 28.0 to before 28.4.1VulnerableErlang
  • cpe:2.3:a:erlang:erlang\/inets:*:*:*:*:*:*:*:* Versions 5.10 to before 9.1.0.5; 9.3 to before 9.3.2.3; 9.6 to before 9.6.1 Vulnerable ·Erlang
  • cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:* Versions 17.0 to before 26.2.5.18; 27.0 to before 27.3.4.9; 28.0 to before 28.4.1 Vulnerable ·Erlang

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-23941

References

Patch 3

Advisory 3

Other 1

  • TI-2026-23002 ScriptAlias CGI targets bypass directory auth in inets httpd (mod_auth vs mod_cgi path mismatch) CVSS 4.0HIGH 8.3
  • TI-2026-36122 ftp client PASV response IP not validated against control peer, enabling SSRF and FTP bounce attacks CVSS 4.0MEDIUM 6.3
  • TI-2026-36121 httpc leaks Authorization header to cross-origin redirect targets CVSS 4.0HIGH 7.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences