# CVE-2026-55480: OpenPrinting CUPS symlink-based file truncation in scheduler

Source: https://junglewise.ai/threats/cve-2026-55480-openprinting-cups-is-an-open-source-printing-system-for-linux-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-15. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-55480 · Severity: medium · CVSS 5.7 · Published 2026-10-15

CUPS is an open-source printing system used on Linux and Unix-like systems. A race condition in the printer scheduling code allows an attacker with local access to predict where temporary files are created, plant a symbolic link, and trick the scheduler running as root into overwriting arbitrary files on the system, potentially compromising critical system files or printer functionality.

Technologies: [OpenPrinting Cups](https://junglewise.ai/threats/technologies/cups). Vendors: [OpenPrinting](https://junglewise.ai/threats/vendors/openprinting).

## Quick answers

**Is CVE-2026-55480 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-55480 being exploited in the wild.

**How severe is CVE-2026-55480?** Medium severity, with a CVSS score of 5.7, published 15 October 2026.

**Which products and versions are affected?** OpenPrinting Cups before 2.4.20.

**Is there a fix for CVE-2026-55480?** Yes: fixed in 2.4.20. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-55480 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-55480?** Check whether you run OpenPrinting Cups at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 2.4.20

## Technical details

The copy_model() function in scheduler/ipp.c creates temporary PPD files in a predictable path (TempDir/<connection-number>.ppd) in a group-writable directory and opens them without O_EXCL or O_NOFOLLOW flags. An attacker with lp group membership can win a race condition by creating a symlink at that predictable path before root opens it, causing the scheduler to follow the symlink and truncate or overwrite an arbitrary file. The attack requires both an existing lp-group foothold and a privileged add-printer or modify-printer operation using a model PPD.

## Affected products

- OpenPrinting CUPS before 2.4.20

## Timeline

- 2026-10-15: disclosed

## References

- [https://github.com/OpenPrinting/cups/commit/98adfd855950e806508f961d5438ad32e26aac62](https://github.com/OpenPrinting/cups/commit/98adfd855950e806508f961d5438ad32e26aac62)
- [https://github.com/OpenPrinting/cups/commit/f6a11dae0f0f3b748fbca931e237be03ffe8e48e](https://github.com/OpenPrinting/cups/commit/f6a11dae0f0f3b748fbca931e237be03ffe8e48e)

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