# CVE-2026-22189: Panda3D egg-mkfont stack buffer overflow in glyph pattern processing

Source: https://junglewise.ai/threats/cve-2026-22189-panda3d-egg-mkfont-stack-buffer-overflow-in-glyph-pattern  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-07. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-22189 · Severity: critical · CVSS 9.8 · Published 2026-01-07

Panda3D is an open-source game engine used for 3D rendering and game development. A vulnerability in its font processing utility, egg-mkfont, allows an attacker to cause a system crash or potentially execute unauthorized code by providing a specially crafted font pattern. This could lead to a loss of system availability or a compromise of the environment where the utility is running.

Technologies: [Cmu Panda3d](https://junglewise.ai/threats/technologies/panda3d). Vendors: [Cmu](https://junglewise.ai/threats/vendors/cmu).

## Quick answers

**Is CVE-2026-22189 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-22189 being exploited in the wild.

**How severe is CVE-2026-22189?** Critical severity, with a CVSS score of 9.8, published 7 January 2026.

**Which products and versions are affected?** Panda3D Panda3D up to and including 1.10.16.

**Is there a fix for CVE-2026-22189?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-22189 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-22189?** Check whether you run Cmu Panda3d. 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.

## Technical details

A stack-based buffer overflow exists in the egg-mkfont utility of Panda3D (<= 1.10.16) within the EggMakeFont::make_tref function. The vulnerability is caused by the use of an unbounded sprintf() call that copies a user-controlled glyph pattern string (provided via the -gp command-line argument) into a fixed-size 1024-byte stack buffer without length validation. An attacker can exploit this by providing an excessively long string, leading to memory corruption and a deterministic crash. Depending on the build environment and presence of stack protections, this may be leveraged for arbitrary code execution. The issue was disclosed in January 2026.

## Affected products

- Panda3D Panda3D up to and including 1.10.16

## Timeline

- 2026-01-01: disclosed: Initial disclosure on Full Disclosure mailing list
- 2026-01-07: advisory: NVD and VulnCheck published advisory data

## References

- [https://github.com/panda3d/panda3d](https://github.com/panda3d/panda3d)
- [https://seclists.org/fulldisclosure/2026/Jan/10](https://seclists.org/fulldisclosure/2026/Jan/10)
- [https://www.panda3d.org/](https://www.panda3d.org/)
- [https://www.vulncheck.com/advisories/panda3d-egg-mkfont-stack-buffer-overflow](https://www.vulncheck.com/advisories/panda3d-egg-mkfont-stack-buffer-overflow)

## Related threats

- [Panda3D egg-mkfont format string vulnerability in -gp option](https://junglewise.ai/threats/cve-2026-22190-panda3d-egg-mkfont-format-string-vulnerability-in-gp-option)
- [Panda3D denial of service via unbounded stack allocation in deploy-stub](https://junglewise.ai/threats/cve-2026-22188-panda3d-denial-of-service-via-unbounded-stack-allocation-in)