CVE-2026-66357

high

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.

References

https://osv.dev/vulnerability/EEF-CVE-2026-66357

https://github.com/erlang/otp/security/advisories/GHSA-qh2f-33hj-37qf

https://github.com/erlang/otp/commit/e640d599287d2eba919e6f13b91f042d7dbe6ff4

https://github.com/erlang/otp/commit/273d8958de38ff2a7fe0c5dcc5b6bfe6f65717f3

https://github.com/erlang/otp/commit/220d618d2479a7180b4a06d0c5aacfaa4af4a85b

https://cna.erlef.org/cves/CVE-2026-66357.html

Details

Source: Mitre, NVD

Published: 2026-09-01

Updated: 2026-09-01

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 8.3

Vector: 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

Severity: High

EPSS

EPSS: 0.00328