High severity · published Aug 15, 2026
CVE-2026-19474
@fastify/multipart vulnerable to Denial of Service via temporary file leak on aborted upload
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
@fastify/multipart is a multipart form-data parser for Fastify. In versions from 3.0.0 up to but not including 10.1.1, request.saveRequestFiles() can leave completed temporary files on disk when a client disconnects while the parser is advancing between multipart parts. The iterator rejection that occurs between parts falls outside the per-file cleanup path, so an earlier completed file is never removed. An unauthenticated client can repeat this to cause persistent, linear disk consumption, leading to denial of service. This is an incomplete-fix variant of CVE-2025-24033. The issue is fixed in @fastify/multipart 10.1.1. Users should upgrade to 10.1.1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FA
@fastify/multipart · @fastify/multipart
3.0.0 before 10.1.1 · source: vendor
FA
Fastify-multipart · Fastify
3.0.0 before 10.1.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-19474
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-19474
Third Party Advisory
https://cna.openjsf.org/security-advisories.html
Mitigation
https://github.com/fastify/fastify-multipart/security/advisories/GHSA-62qx-hpj5-j6hc
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