What’s Vulnerable › Vulnerabilities

CVE-2023-25576: @fastify/multipart vulnerable to DoS due to unlimited number of parts

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-02-14 · updated 2026-06-17
• Weakness: CWE-770

Description

@fastify/multipart is a Fastify plugin to parse the multipart content-type. Prior to versions 7.4.1 and 6.0.1, @fastify/multipart may experience denial of service due to a number of situations in which an unlimited number of parts are accepted. This includes the multipart body parser accepting an unlimited number of file parts, the multipart body parser accepting an unlimited number of field parts, and the multipart body parser accepting an unlimited number of empty parts as field parts. This is fixed in v7.4.1 (for Fastify v4.x) and v6.0.1 (for Fastify v3.x). There are no known workarounds.

Affected products

• fastify-multipart: before 6.0.1; from 7.0.0 before 7.4.1 — fixed in 6.0.1, 7.4.1

How to fix

Upgrade to a fixed version: fastify-multipart 6.0.1, 7.4.1. Check the vendor advisory for mitigations.

References

• https://github.com/fastify/fastify-multipart/commit/85be81bedf5b29cfd9fe3efc30fb5a17173c1297
• https://github.com/fastify/fastify-multipart/releases/tag/v6.0.1
• https://github.com/fastify/fastify-multipart/releases/tag/v7.4.1
• https://github.com/fastify/fastify-multipart/security/advisories/GHSA-hpp2-2cr5-pf6g
• https://hackerone.com/reports/1816195
• https://github.com/fastify/fastify-multipart/commit/85be81bedf5b29cfd9fe3efc30fb5a17173c1297
• https://github.com/fastify/fastify-multipart/releases/tag/v6.0.1
• https://github.com/fastify/fastify-multipart/releases/tag/v7.4.1
• https://github.com/fastify/fastify-multipart/security/advisories/GHSA-hpp2-2cr5-pf6g
• https://hackerone.com/reports/1816195

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