multer vulnerable to Denial of Service via a pending asynchronous fileFilter after request teardown
CVE-2026-113872
Impact When multer is configured with an asynchronous fileFilter, a single request can crash the Node.js process. If a request is aborted (for example when one file is rejected) while another file's async fileFilter is still pending, the pending callback later resumes a parsing stream that multer has already torn down. busboy then emits an error on a stream that no longer has an error listener, which Node raises as an unhandled 'error' event, and the process exits. A single unauthenticated request is enough, so any application using multer with an asynchronous fileFilter is affected, regardless of storage engine. Uploads using a synchronous fileFilter are not affected. Patches Users should upgrade to multer 2.5.0 or later. Workarounds Use a synchronous fileFilter.
Proof-of-concept code is published
Public PoC
- Public PoCsantihabib/multer-CVE-2026-113872
Signals come from Exploit-DB, Metasploit, Nuclei and published proof-of-concept repositories. Their absence means nothing was found, not that nothing exists.
Assessment
- CVSS
- 7.5 (v3.1)
- Severity
- High
- EPSS
- 0.00442% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Public PoC
- Published
- 23 October 2026
- Last updated
- 23 October 2026
- Affected
- npm · multer
- Weakness
- CWE-248, CWE-404
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
At the source
References
- https://github.com/expressjs/multer/security/advisories/GHSA-q7qp-rjg7-q26m
- https://nvd.nist.gov/vuln/detail/CVE-2026-113872
- https://github.com/expressjs/multer/commit/80a2d9df1dfd63b5fab631b8b9966164ed647adf
- https://cna.openjsf.org/security-advisories.html
- https://github.com/expressjs/multer/releases/tag/v2.5.0
- https://github.com/advisories/GHSA-q7qp-rjg7-q26m
Community proofs of concept
No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.
Submit a proof of concept
Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.
Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://cve.zerocrew.in/api/cve/CVE-2026-113872