CVE-2026-34980: CWE-20: Improper Input Validation in OpenPrinting cups
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At time of publication, there are no publicly available patches.
AI Analysis
Technical Summary
OpenPrinting CUPS versions 2.4.16 and prior contain an improper input validation vulnerability (CWE-20) in the network-exposed cupsd service when using a shared target queue. An unauthenticated attacker can submit a Print-Job with a specially crafted page-border value that includes embedded newlines. The server preserves these newlines through option escaping and reparsing, which causes the second line of the PPD text to be interpreted as a trusted scheduler control record. This flaw allows a follow-up raw print job to execute an existing binary on the server, such as /usr/bin/vim, running as the lp user. The CVSS 4.0 base score is 6.1, reflecting medium severity with attack vector as adjacent network and no privileges required.
Potential Impact
An attacker with network access to a vulnerable CUPS server configured with a shared target queue can submit print jobs without authentication and leverage improper input validation to execute arbitrary existing binaries on the server with lp user privileges. This could lead to unauthorized code execution and potential further compromise of the system. There are no known public exploits in the wild at this time.
Mitigation Recommendations
At the time of this advisory, no patches or official fixes are available for this vulnerability. Users should monitor the OpenPrinting project for updates and advisories. As a temporary mitigation, restricting network exposure of the cupsd service and disabling shared target queues where possible may reduce risk. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
CVE-2026-34980: CWE-20: Improper Input Validation in OpenPrinting cups
Description
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At time of publication, there are no publicly available patches.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OpenPrinting CUPS versions 2.4.16 and prior contain an improper input validation vulnerability (CWE-20) in the network-exposed cupsd service when using a shared target queue. An unauthenticated attacker can submit a Print-Job with a specially crafted page-border value that includes embedded newlines. The server preserves these newlines through option escaping and reparsing, which causes the second line of the PPD text to be interpreted as a trusted scheduler control record. This flaw allows a follow-up raw print job to execute an existing binary on the server, such as /usr/bin/vim, running as the lp user. The CVSS 4.0 base score is 6.1, reflecting medium severity with attack vector as adjacent network and no privileges required.
Potential Impact
An attacker with network access to a vulnerable CUPS server configured with a shared target queue can submit print jobs without authentication and leverage improper input validation to execute arbitrary existing binaries on the server with lp user privileges. This could lead to unauthorized code execution and potential further compromise of the system. There are no known public exploits in the wild at this time.
Mitigation Recommendations
At the time of this advisory, no patches or official fixes are available for this vulnerability. Users should monitor the OpenPrinting project for updates and advisories. As a temporary mitigation, restricting network exposure of the cupsd service and disabling shared target queues where possible may reduce risk. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-31T19:38:31.617Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d031770a160ebd925d2016
Added to database: 4/3/2026, 9:30:31 PM
Last enriched: 4/11/2026, 9:27:27 AM
Last updated: 5/20/2026, 9:37:01 PM
Views: 97
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