CVE-2026-55453
Published: October 7, 2026Last modified: October 16, 2026
Description
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 3.3 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | LOW |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | cups | Fixed (2.4.20-r0) |
| 25 LTS | cups | Fixed (2.4.20-r0) | |
| Stream | cups | Fixed (2.4.20-r0) |
References
- https://github.com/OpenPrinting/cups/commit/806e1b483096c51d59432468f4afdd7387d81dd7
- https://github.com/OpenPrinting/cups/commit/d41cf0616688721e9d435d54118c4c8a36ed596a
- https://github.com/OpenPrinting/cups/releases/tag/v2.4.20
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-7hqf-mfhx-7r3v