CVE-2026-66357
httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines).
Impact
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.
Affected products
| Product | Affected versions |
|---|---|
| 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 |
Versions were read from the advisory text. No structured product data has been published for this record yet.
Weakness classification
References
- NVD record
- CVE.org record
- https://cna.erlef.org/cves/CVE-2026-66357.html
- https://github.com/erlang/otp/commit/220d618d2479a7180b4a06d0c5aacfaa4af4a85b
- https://github.com/erlang/otp/commit/273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3
- https://github.com/erlang/otp/commit/e640d599287d2eba919e6f13b91f042d7dbe6ff4
- https://github.com/erlang/otp/security/advisories/GHSA-qh2f-33hj-37qf
- https://osv.dev/vulnerability/EEF-CVE-2026-66357