# CVE-2026-120433: Netpbm stack buffer overflow in picttoppm paintPoly

Source: https://junglewise.ai/threats/cve-2026-120433-netpbm-before-10-86-51-11-x-before-11-02-30-and-11-03-before-11  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-02. Updated: 2026-11-02  
License: CC BY 4.0 with a link back

CVE-2026-120433 · Severity: high · CVSS 7.8 · Published 2026-11-02

Netpbm is a suite of image conversion and graphics manipulation tools used to translate between different image formats. A stack-based buffer overflow in the picttoppm converter allows attackers to crash the application or potentially execute arbitrary code by supplying a specially crafted PICT image file with an oversized polygon.

Technologies: [Netpbm](https://junglewise.ai/threats/technologies/netpbm). Vendors: [Netpbm](https://junglewise.ai/threats/vendors/netpbm).

## Quick answers

**Is CVE-2026-120433 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120433 being exploited in the wild.

**How severe is CVE-2026-120433?** High severity, with a CVSS score of 7.8, published 2 November 2026.

**Which products and versions are affected?** Netpbm before 10.86.51, 11.x before 11.02.30, 11.03 before 11.15.08.

**Is there a fix for CVE-2026-120433?** Yes: fixed in 10.86.51, 11.02.30, 11.15.08. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-120433 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-120433?** Check whether you run Netpbm 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 10.86.51, 11.02.30, 11.15.08

## Technical details

The picttoppm paintPoly() function fails to validate the polygon point count before writing to a fixed-size stack array, allowing a crafted PICT file with a polygon exceeding 100 points to overwrite the pts array. The vulnerability is triggered when processing a malicious PICT file, requiring no authentication or user interaction beyond opening the file. An attacker can achieve denial of service or code execution depending on the overwritten stack contents.

## Affected products

- Netpbm Netpbm before 10.86.51, 11.x before 11.02.30, 11.03 before 11.15.08

## Timeline

- 2026-11-02: disclosed: CVE-2026-120433 published
- 2026-09-09: patched: Fix committed to repository (commit r5328)

## References

- [https://sourceforge.net/p/netpbm/code/5328/](https://sourceforge.net/p/netpbm/code/5328/)
- [https://svn.code.sf.net/p/netpbm/code/!svn/bc/5327/trunk/converter/ppm/picttoppm.c](https://svn.code.sf.net/p/netpbm/code/!svn/bc/5327/trunk/converter/ppm/picttoppm.c)

## Related threats

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- [Netpbm jbigtopnm integer overflow heap buffer overflow](https://junglewise.ai/threats/cve-2026-120436-netpbm-before-10-86-51-11-x-before-11-02-30-and-11-03-before-11)
- [Netpbm heap buffer overflow in xpmtoppm](https://junglewise.ai/threats/cve-2026-120435-netpbm-before-10-86-51-11-x-before-11-02-30-and-11-03-before-11)
- [Netpbm stack buffer overflow in picttoppm scanPoly()](https://junglewise.ai/threats/cve-2026-120434-netpbm-before-10-86-51-11-x-before-11-02-30-and-11-03-before-11)
- [Netpbm integer overflow in winicontopam](https://junglewise.ai/threats/cve-2026-120432-netpbm-before-10-86-51-11-02-30-and-11-15-08-contains-an-integer)