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TI-2026-15859 Aliases CVE-2026-19474

@fastify/multipart vulnerable to Denial of Service via temporary file leak on aborted upload

Priority LOW 39CWE-459Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

@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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00493 42nd percentileScored 2026-11-07
Fix Fixed @fastify/multipart (@fastify/multipart): 10.1.1

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

VendorProductAffected versionsFixed inStatusSource
@fastify/multipart@fastify/multipart3.0.0 to before 10.1.110.1.1Patch availableCNA
  • @fastify/multipart Vendor@fastify/multipart Affected 3.0.0 to before 10.1.1 Fixed in 10.1.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:fastify:fastify-multipart:*:*:*:*:*:fastify:*:*3.0.0 to before 10.1.1Vulnerablefastify
  • cpe:2.3:a:fastify:fastify-multipart:*:*:*:*:*:fastify:*:* Versions 3.0.0 to before 10.1.1 Vulnerable ·fastify

Remediation

  • Fix · CNA @fastify/multipart (@fastify/multipart) Fixed in 10.1.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    @fastify/multipart 10.1.1

    2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-15210 @fastify/multipart vulnerable to Denial of Service via aborted upload after fileSize limitPriority MEDIUM 40
    Show all 2 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-19474

References

Advisory 2

  • TI-2026-83783 Denial of service in @fastify/multipart from malformed file uploads CVSS 3.1MEDIUM 5.9

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences