TI-2025-23513 Aliases CVE-2025-32442 GHSA-mg2h-6x62-wpwc

Fastify vulnerable to invalid content-type parsing, which could lead to validation bypass

MEDIUM 40CWE-1287Published 2025-04-18 · Updated 2025-08-22

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · High · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00729 54th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed fastify (fastify): 5.3.2fastify (npm): 5.3.2, 4.29.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
fastify	fastify	5.0.0 to before 5.3.2; = 4.29.0	5.3.2	Patch available	CNA
—	fastify (npm)	5.0.0 to before 5.3.2	5.3.2	Patch available	GHSA-mg2h-6x62-wpwc
—	fastify (npm)	4.29.0 to before 4.29.1	4.29.1	Patch available	GHSA-mg2h-6x62-wpwc

fastify Vendorfastify Affected 5.0.0 to before 5.3.2; = 4.29.0 Fixed in 5.3.2 Patch available CNA
fastify (npm) Vendor— Affected 5.0.0 to before 5.3.2 Fixed in 5.3.2 Patch available GHSA-mg2h-6x62-wpwc
fastify (npm) Vendor— Affected 4.29.0 to before 4.29.1 Fixed in 4.29.1 Patch available GHSA-mg2h-6x62-wpwc

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:fastify:fastify::::::node.js::*	5.0.0 to before 5.3.2	Vulnerable	fastify
cpe:2.3:a:fastify:fastify:4.29.0:::::node.js::	4.29.0	Vulnerable	fastify

cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:* Versions 5.0.0 to before 5.3.2 Vulnerable ·fastify
cpe:2.3:a:fastify:fastify:4.29.0:*:*:*:*:node.js:*:* Versions 4.29.0 Vulnerable ·fastify

Remediation

Fix · CNA fastify (fastify) Fixed in 5.3.2
Fix · GHSA-mg2h-6x62-wpwc fastify (npm) Fixed in 5.3.2 Advisory →
Fix · GHSA-mg2h-6x62-wpwc fastify (npm) Fixed in 4.29.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Not affected: 2 products

OpenShift Serverless
Red Hat OpenShift AI (RHOAI)

Timeline

2026-10-02 Threatist record created from CVE-2025-32442
2026-10-03 Alias added: GHSA-mg2h-6x62-wpwc

References

Exploit 1

https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc

Patch 2

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2025-32442

Other 2

TI-2022-18664 Denial of service in Fastify via Content-Type header CVSS 3.1HIGH 7.5
TI-2026-58050 fastify vulnerable to request validation bypass via skipped boolean false schemas CVSS 3.1HIGH 7.5
TI-2026-58022 fastify vulnerable to header validation bypass via incomplete schema case normalization CVSS 3.1HIGH 7.5
TI-2026-53284 fastify vulnerable to authentication bypass via malformed URLs reaching encapsulated not-found handlers CVSS 3.1HIGH 7.5
TI-2026-26178 fastify vulnerable to Body Schema Validation Bypass via Leading Space in Content-Type Header CVSS 3.1HIGH 7.5
TI-2026-58072 fastify vulnerable to request body replacement via an async validation result collision CVSS 3.1HIGH 8.1

See all 15 →

Sources

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