CVE-2026-55480
mediumOpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems.
Vendor / product: Openprinting — cups
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/.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.
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/OpenPrinting/cups/commit/98adfd855950e806508f961d5438ad32e26aac62 security-advisories@github.com
- https://github.com/OpenPrinting/cups/commit/f6a11dae0f0f3b748fbca931e237be03ffe8e48e security-advisories@github.com
- https://github.com/OpenPrinting/cups/releases/tag/v2.4.20 security-advisories@github.com
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-jj94-x3qh-ffp9 security-advisories@github.com
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-jj94-x3qh-ffp9 134c704f-9b21-4f2e-91b3-4a467353bcc0