CVE-2026-3520
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.71%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.71% probability · 52th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-674, CWE-770
- Affected
- expressjs/multer
- Source
- ce714d77-add3-4f53-aff5-83d477b104bb
References
- https://cna.openjsf.org/security-advisories.htmlThird Party Advisory
- https://github.com/expressjs/multer/commit/7e66481f8b2e6c54b982b34c152479e096ce2752Patch
- https://github.com/expressjs/multer/security/advisories/GHSA-5528-5vmv-3xc2Vendor Advisory
- https://www.cve.org/CVERecord?id=CVE-2026-3520Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:6174
- https://access.redhat.com/errata/RHSA-2026:6802
- https://access.redhat.com/security/cve/CVE-2026-3520
- https://bugzilla.redhat.com/show_bug.cgi?id=2444584
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3520.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.