CVE-2026-66357
inets,httpd:HTTP Request Smuggling via obs-fold Header Continuation
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, OTP 28.5.0.6, and OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, 9.6.2.3, and 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: EEFFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: EEFFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: EEFAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| OTP Erlang otp
software-id |
≥ 17.0; < * (affected, otp); unaffected at 27.3.4.17; unaffected at 28.5.0.6; unaffected at 29.0.6
Other versions: unknown |
CNA: EEF |
| OTP Erlang inets
otp |
≥ 5.10; < * (affected, otp); unaffected at 9.3.2.7; unaffected at 9.6.2.3; unaffected at 9.7.2
Other versions: unknown |
CNA: EEF |
| OTP Erlang erlang/otp
github |
≥ 84adefa331c4159d432d22840663c38f155cd4c1; < * (affected, git); unaffected at 220d618d2479a7180b4a06d0c5aacfaa4af4a85b; unaffected at 273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3; unaffected at e640d599287d2eba919e6f13b91f042d7dbe6ff4 ≥ 220d618d2479a7180b4a06d0c5aacfaa4af4a85b; < * (unaffected, git) ≥ 273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3; < * (unaffected, git) ≥ e640d599287d2eba919e6f13b91f042d7dbe6ff4; < * (unaffected, git) Other versions: unknown |
CNA: EEF |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 8.3 high |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:L/SA:N | CNA: EEF |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/erlang/otp/security/advisories/GHSA-qh2f-33hj-37qfCNA: EEF · vendor-advisory
- https://cna.erlef.org/cves/CVE-2026-66357.htmlCNA: EEF · related
- https://osv.dev/vulnerability/EEF-CVE-2026-66357CNA: EEF · related
- https://www.erlang.org/doc/system/versions.html#order-of-versionsCNA: EEF · x_version-scheme
- https://github.com/erlang/otp/commit/220d618d2479a7180b4a06d0c5aacfaa4af4a85bCNA: EEF · patch
- https://github.com/erlang/otp/commit/273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3CNA: EEF · patch
- https://github.com/erlang/otp/commit/e640d599287d2eba919e6f13b91f042d7dbe6ff4CNA: EEF · patch
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