CVE-2026-66357: CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in Erlang OTP
httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved. 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.
CVE-2026-66357: CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in Erlang OTP
Description
httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understanding of HTTP request smuggling attacks evolved. 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.
CVSS v4.0
Score 8.3high
Affected software
pkg:github/inetscpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- EEF
- Date Reserved
- 2026-08-17T20:00:02.207Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a96e6ecacd9273b49d7167b
Added to database: 09/01/2026, 14:53:32 UTC
Last updated: 09/01/2026, 15:38:34 UTC
Views: 3
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