OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_banner() in scheduler/ipp.c uses the attacker-controlled IPP attributes-natural-language value as a directory component beneath DataDir/banners when processing a job-sheets banner. The job-sheets value must first match a registered banner basename, and the traversed path must contain a matching reachable basename; selecting an arbitrary target as demonstrated additionally requires pre-positioned path state such as a symlink with that basename. Subject to the scheduler's filesystem and sandbox access, path separators in the language value can escape the intended banner directory, make the root scheduler open the reachable file, and copy its bytes into a job-sheet spool object that a configured backend can deliver to an attacker-observable endpoint. This issue is fixed in version 2.4.20.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/OpenPrinting/cups/commit/08a8a277ce2a8948a1af33552247a1ac53b72df3 Patch
- https://github.com/OpenPrinting/cups/commit/6650428234616a97d3298e0e2d4419c62c1339d2 Patch
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-gq9p-4w7m-2f5g Exploit, Mitigation, Vendor Advisory
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-gq9p-4w7m-2f5g Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 5
- StatusAnalyzed → ModifiedNVD modified 2026-10-28 21:17
- Cpes+1 CPE criteria (now 1)NVD modified 2026-10-20 19:08
- StatusAwaiting Analysis → AnalyzedNVD modified 2026-10-20 19:08
- StatusReceived → Awaiting AnalysisNVD modified 2026-10-16 16:00
- First seenCVSS 5.3NVD modified 2026-10-15 18:17
Affected (CPE criteria) 1
cpe:2.3:a:openprinting:cups:*:*:*:*:*:*:*:*
References 5
- https://github.com/OpenPrinting/cups/commit/08a8a277ce2a8948a1af33552247a1ac53b72df3 Patch
- https://github.com/OpenPrinting/cups/commit/6650428234616a97d3298e0e2d4419c62c1339d2 Patch
- https://github.com/OpenPrinting/cups/releases/tag/v2.4.20 Release Notes
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-gq9p-4w7m-2f5g Exploit, Mitigation, Vendor Advisory
- https://github.com/OpenPrinting/cups/security/advisories/GHSA-gq9p-4w7m-2f5g Exploit, Mitigation, Vendor Advisory