CVE-2026-55453 — CUPS ipp backend status-line injection can update queue PPD and lead to conditional RCE as lp via foomatic-rip
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, the backend/ipp.c quote_string() function preserves carriag…
Published: 2026-10-15 · CVSS: 3.3 · CVSS 3.1
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, the backend/ipp.c quote_string() function preserves carriage-return and line-feed characters in a remote printer-controlled marker-message before report_attr() writes the value to the scheduler status stream. The scheduler can parse an injected newline as a separate PPD: control line and persist an attacker-selected PPD keyword. The reporter demonstrated that a later print job on a Foomatic-backed queue could consume an injected FoomaticRIPCommandLine value and execute in the filter context as lp. This issue is fixed in version 2.4.20.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7