Link following in cups - CVE-2026-55480
Published: June 17, 2026
Vulnerability identifier: #VU134734
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-55480
CWE-ID: CWE-59
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: OpenPrinting
Affected software:
cups
cups
Detailed vulnerability description
The vulnerability allows a local privileged user to overwrite arbitrary root-owned files and escalate privileges.
The vulnerability exists due to improper link resolution before file access in copy_model() in scheduler/ipp.c when creating a predictable temporary PPD file in a group-writable temporary directory. A local privileged user can pre-create a symlink at the predicted tempfile path to overwrite arbitrary root-owned files and escalate privileges.
The issue depends on a predictable tempfile name derived from the sequential client connection identifier, and exploitation targets the add or modify printer code path.
How to mitigate CVE-2026-55480
Install security update from vendor's website.