Findings

Security fix · CVE-2025-32442

Fastify is a fast and low overhead web framework, for Node.js.

Published Apr 18, 2025 · corrected/updated Aug 22, 2025 · fastify fastify · evidence confidence high

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.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2025-32442 is a high public vulnerability record for fastify fastify. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether fastify fastify is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: fastify fastify 5.0.0, < 5.3.1 (5.0.0, < 5.3.1). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 7.5, EPSS 72.0%. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: euvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 18, 2025 · EUVD

    Detected

    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 pat

  2. Aug 22, 2025 · EUVD

    Updated

    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 pat

Affected

  • vendor fastify fastify 5.0.0, < 5.3.15.0.0, < 5.3.1

Sources

  • EUVDVulnerability recordEUVD-2025-11842

    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_ con

    euvd.enisa.europa.eu

References