CVE-2026-103930

Name	CVE-2026-103930
Description	cpp-httplib is a C++ header-only HTTP/HTTPS library. From 0.29.0 until 0.51.0, Client::open_stream in httplib.h accepts a caller-controlled path that reaches detail::write_request_line() without the detail::encode_path() protection used by the ordinary buffered request path. Raw carriage-return and line-feed bytes in the path can therefore split the outbound HTTP/1.1 request line and inject attacker-shaped request metadata. Exploitation requires an embedding application to pass remote user input into the open_stream path and a backend or intermediary that interprets the injected bytes; the established impact is modification of backend-visible request data, not direct confidentiality or availability impact. This issue is fixed in version 0.51.0.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1151203

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
cpp-httplib (PTS)	bookworm	0.11.4+ds-1+deb12u1	vulnerable
	trixie (security), trixie	0.18.7-1+deb13u1	vulnerable
	forky, sid	0.41.0+ds-3	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
cpp-httplib	source	(unstable)	(unfixed)			1151203

Notes

https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-vq69-f637-8fhr
https://github.com/yhirose/cpp-httplib/pull/2501
Fixed by: https://github.com/yhirose/cpp-httplib/commit/255c075b82cf9f221e6e607e8e6789e6e2bf4c2a (v0.51.0)