Multer vulnerable to Denial of Service via uncontrolled recursion
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.7%
exploitation probability
0.7%top 50% of all CVEs
observed exploitation
nono source reports it
Multer is a node.js middleware for handling `multipart/form-data`. A vulnerability in Multer prior to version 2.1.1 allows an attacker to trigger a Denial of Service (DoS) by sending malformed requests, potentially causing stack overflow. Users should upgrade to version 2.1.1 to receive a patch. No known workarounds are available.
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
Affected products
expressjs · multerReferences
https://access.redhat.com/errata/RHSA-2026:6174https://access.redhat.com/errata/RHSA-2026:6802https://access.redhat.com/security/cve/CVE-2026-3520https://bugzilla.redhat.com/show_bug.cgi?id=2444584https://cna.openjsf.org/security-advisories.htmlhttps://github.com/expressjs/multer/commit/7e66481f8b2e6c54b982b34c152479e096ce2752https://github.com/expressjs/multer/security/advisories/GHSA-5528-5vmv-3xc2https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3520.jsonhttps://www.cve.org/CVERecord?id=CVE-2026-3520