CVE-2026-27447

Name	CVE-2026-27447
Description	OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, CUPS daemon (cupsd) contains an authorization bypass vulnerability due to case-insensitive username comparison during authorization checks. The vulnerability allows an unprivileged user to gain unauthorized access to restricted operations by using a user with a username that differs only in case from an authorized user. At time of publication, there are no publicly available patches.
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	1132716

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
cups (PTS)	bullseye	2.3.3op2-3+deb11u8	vulnerable
	bullseye (security)	2.3.3op2-3+deb11u10	vulnerable
	bookworm, bookworm (security)	2.4.2-3+deb12u9	vulnerable
	trixie	2.4.10-3+deb13u2	vulnerable
	trixie (security)	2.4.10-3+deb13u1	vulnerable
	forky	2.4.16-1	vulnerable
	sid	2.4.17-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
cups	source	(unstable)	2.4.17-1			1132716

Notes

[trixie] - cups <no-dsa> (Minor issue)
[bookworm] - cups <no-dsa> (Minor issue)
https://github.com/OpenPrinting/cups/security/advisories/GHSA-v987-m8hp-phj9
Fixed by: https://github.com/OpenPrinting/cups/commit/88516bf6d9e34cef7a64a704b856b837f70cd220
Fixed by: https://github.com/OpenPrinting/cups/commit/a0c62c1e69604ff061089b750073199fab5a1beb (v2.4.17)