Multer Vulnerable to Denial of Service via Uncontrolled Recursion

Description

Impact

A vulnerability in Multer versions < 2.1.1 allows an attacker to trigger a Denial of Service (DoS) by sending malformed requests, potentially causing stack overflow.

Patches

Users should upgrade to 2.1.1

Workarounds

None

Resources

  • https://github.com/expressjs/multer/security/advisories/GHSA-5528-5vmv-3xc2
  • https://www.cve.org/CVERecord?id=CVE-2026-3520
  • https://github.com/expressjs/multer/commit/7e66481f8b2e6c54b982b34c152479e096ce2752
  • https://cna.openjsf.org/security-advisories.html

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-05 00:27:50 UTC
Updated
2026-03-05 00:27:52 UTC
GitHub reviewed
2026-03-05 00:27:50 UTC
NVD published
2026-03-04 17:16:22 UTC

EPSS Score

Score Percentile
0.06% 20.00%

CVSS Scores

Base score Version Severity Vector
8.7 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

CWEs

CWE id Name
CWE-674 Uncontrolled Recursion

Credits

  • yuki-matsuhashi (reporter)
  • ctcpip (remediation_developer)
  • UlisesGascon (remediation_reviewer)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm multer < 2.1.1 2.1.1

References

cvelogic Threat Intelligence