OpenPrinting CUPS up to 2.4.19 IPP Backend backend/ipp.c quote_string injection

Summaryinfo

A vulnerability classified as critical has been found in OpenPrinting CUPS up to 2.4.19. This affects the function quote_string of the file backend/ipp.c of the component IPP Backend. Performing a manipulation results in injection. This vulnerability is identified as CVE-2026-55453. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in OpenPrinting CUPS up to 2.4.19. This affects the function quote_string of the file backend/ipp.c of the component IPP Backend. The manipulation with an unknown input leads to a injection vulnerability. CWE is classifying the issue as CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. This is going to have an impact on availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-55453 since 06/17/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1055 for this issue.

Upgrading to version 2.4.20 eliminates this vulnerability.

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Productinfo

Type

• Printing Software

Vendor

• OpenPrinting

Name

• CUPS

Version

• 2.4.0
• 2.4.1
• 2.4.2
• 2.4.3
• 2.4.4
• 2.4.5
• 2.4.6
• 2.4.7
• 2.4.8
• 2.4.9
• 2.4.10
• 2.4.11
• 2.4.12
• 2.4.13
• 2.4.14
• 2.4.15
• 2.4.16
• 2.4.17
• 2.4.18
• 2.4.19

Website

• Product: https://github.com/OpenPrinting/cups/

CPE 2.3info

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CPE 2.2info

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