CVE-2026-33864
Critical · 9.3Convict has Prototype Pollution via startsWith() function
CVSS
9.3
EPSS
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Published
Mar 26, 2026
CISA due date
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The record
A prototype pollution vulnerability exists in the latest version of the convict npm package (6.2.4). Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input started with a forbidden key, it is still possible to pollute `Object.prototype` via a crafted input using `String.prototype`.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| npm | convict | 0 | 6.2.5 |
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- GHSA-44fc-8fm5-q62h Convict has Prototype Pollution via startsWith() function Same vulnerability
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