Improper Authentication Affecting cups package, versions <2.4.18-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.29% (21st percentile)

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  • Snyk IDSNYK-ALPINE321-CUPS-16335100
  • published1 May 2026
  • disclosed3 Apr 2026

Introduced: 3 Apr 2026

CVE-2026-34990  (opens in a new tab)
CWE-287  (opens in a new tab)

How to fix?

Upgrade Alpine:3.21 cups to version 2.4.18-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream cups package and not the cups package as distributed by Alpine. See How to fix? for Alpine:3.21 relevant fixed versions and status.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a local unprivileged user can coerce cupsd into authenticating to an attacker-controlled localhost IPP service with a reusable Authorization: Local ... token. That token is enough to drive /admin/ requests on localhost, and the attacker can combine CUPS-Create-Local-Printer with printer-is-shared=true to persist a file:///... queue even though the normal FileDevice policy rejects such URIs. Printing to that queue gives an arbitrary root file overwrite; the PoC below uses that primitive to drop a sudoers fragment and demonstrate root command execution. At time of publication, there are no publicly available patches.

CVSS Base Scores

version 3.1