Uncaught Exception Affecting multer package, versions <2.3.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-MULTER-19432021
- published30 Aug 2026
- disclosed29 Aug 2026
- creditLuke Lucas
Introduced: 29 Aug 2026
NewCVE-2026-77078 (opens in a new tab)How to fix?
Upgrade multer to version 2.3.0 or higher.
Overview
Affected versions of this package are vulnerable to Uncaught Exception via the appendField call in make-middleware.js when processing multipart form field names. An attacker submitting a malformed or invalid field name in a multipart upload request causes an unhandled exception that crashes the process. The fix wraps the appendField call in a try/catch and aborts with an INVALID_FIELD_NAME error code instead of propagating the exception.