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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-55453)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-55453)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of cups installed on the remote host is prior to 2.4.19 / 2.4.20. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2026-278-01 advisory.

    New cups packages are available for Slackware 15.0 and -current to fix security issues.

Tenable has extracted the preceding description block directly from the cups security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Type	Severity
474857	Echo: cups: security update to 2.4.20-1	Tenable Cloud Security	Echo Local Security Checks	Local	low
474857	Echo: cups: security update to 2.4.20-1	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	low
363053	Linux Distros Unpatched Vulnerability : CVE-2026-55453	Nessus	Misc.	Local	low
363018	Slackware Linux 15.0 / current cups Multiple Vulnerabilities (SSA:2026-278-01)	Nessus	Slackware Local Security Checks	Local	medium

Detections

Analytics

CVE-2026-55453

low

Tenable Plugins

low

low

low

medium