Cups: Prior to 2.4.20, copy_banner()
Affects cupsSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium · fixed in 2.4.20 : update cups when convenient.
Data as of 28 Oct 2026, 22:28 UTC
- Patch
- Available – fixed in 2.4.20
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 15 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10cupspkg:deb/ubuntu/cups?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTScupspkg:deb/ubuntu/cups?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTScupspkg:deb/ubuntu/cups?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTScupspkg:deb/ubuntu/cups?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTScupspkg:deb/ubuntu/cups?arch=source&distro=esm-infra/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTScupspkg:deb/ubuntu/cups?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.