CVE-2026-54388

Name	CVE-2026-54388
Description	Tinyproxy through 1.11.3, fixed in commit 364cdb6, fails to reject requests containing multiple Content-Length headers with differing values, forwarding all duplicate headers to the backend while using the first value to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.
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)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
tinyproxy (PTS)	bullseye	1.10.0-5	vulnerable
	bullseye (security)	1.10.0-5+deb11u1	vulnerable
	bookworm, bookworm (security)	1.11.1-2.1+deb12u1	vulnerable
	trixie	1.11.2-1	vulnerable
	sid, forky	1.11.3-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
tinyproxy	source	(unstable)	(unfixed)

Notes

[trixie] - tinyproxy <no-dsa> (Minor issue)
https://github.com/tinyproxy/tinyproxy/issues/609
https://github.com/tinyproxy/tinyproxy/pull/610
Fixed by: https://github.com/tinyproxy/tinyproxy/commit/364cdb67e0ea00a8e4a7037e2693e0711e816adb