CVE-2026-55480 CUPS copy_model() creates a predictable PPD tempfile without O_EXCL/O_NOFOLLOW (symlink TOCTOU, lp → root)
A local attacker with lp-group access can exploit a race condition in CUPS to overwrite root-owned files via symlink attacks during printer model copying.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55480?
CVE-2026-55480 is a medium-severity vulnerability in OpenPrinting cups, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_model() in scheduler/ipp.c creates a predictable TempDir/<connection-number>.ppd path in an lp-group-writable directory and opens it as root without O_EXCL or O_NOFOLLOW. Exploitation requires an lp-group process able to write that directory to predict the connection-derived name and plant a symlink before the root open, while a privileged add-printer or modify-printer operation using a model PPD triggers copy_model(). The reporter treats an existing lp foothold and the privileged operation as distinct prerequisites, while the maintainer assesses high privileges because installing the relevant filter or administering the printer requires root or print-administrator access. If the race succeeds, the root scheduler follows the symlink and truncates or overwrites a root-writable target with generated PPD data, compromising file integrity or availability. This issue is fixed in version 2.4.20.
Which versions are affected by CVE-2026-55480?
It affects 1 product.
Products include Openprinting Cups.
How do I fix CVE-2026-55480?
Upgrade to a fixed version.
Is CVE-2026-55480 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55480 exists.
Other vulnerabilities in OpenPrinting cups
- CVE-2025-58060 cups has Authentication bypass with AuthType Negotiate
- CVE-2026-34978 Path traversal in cups
- CVE-2025-58364 cups: Remote DoS via null dereference
- CVE-2026-34980 OpenPrinting CUPS: Shared PostScript queue lets anonymous Print-Job requests reach `lp` code execution over the network
- CVE-2025-61915 OpenPrinting CUPS vulnerable to stack based out-of-bound write
Sources
Also known as AZL-108284, BELL-CVE-2026-55480, DEBIAN-CVE-2026-55480, ECHO-ffb1-08bb-e5b4, GHSA-jj94-x3qh-ffp9, UBUNTU-CVE-2026-55480.