Microsoft Security Response Center guidance
Vendor revision: Oct 17, 2026Release Notes
Vulnerability intelligence
CVE-2026-55453 and is rated Low severity with a CVSS score of 3.3. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
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: NVD