PatchTheCVECVE-2026-34978: OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems
CVE-2026-34978 is a medium-severity flaw (CVSS 6.5) affecting cups. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, the RSS notifier allows .. path traversal in notify-recipient-uri (e.g., rss:///../job.cache), letting a remote IPP client write RSS XML bytes outside CacheDir/rss (anywhere that is lp-writable). In particular, because CacheDir is group-writable by default (typically root:lp and mode 0770), the notifier (running as lp
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 65%) |
| CISA exploited list | No |
| Weakness | CWE-22 |
| Published | 2026-04-03 |
| Last modified | 2026-07-20 |
Last updated 2026-07-20 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-34978?
cups: upgrade to newer than 2.4.16. Exact commands for each OS are on this page.
Is CVE-2026-34978 being exploited?
CVE-2026-34978 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-34978 affect?
CVE-2026-34978 affects cups. Severity is medium (CVSS 6.5). OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, the RSS notifier allows .. path traversal in notify-recipient-uri (e.g., rss:///../job.cache), letting a remo
How urgent is CVE-2026-34978?
Priority 46/100. Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist
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