Description
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Before 2.5.6, a prior patch aimed to block spawning Windows batch/shell files by returning an error when a spawned path’s extension matched .bat or .cmd. That check performs a case-sensitive comparison against lowercase literals and therefore can be bypassed when the extension uses alternate casing (for example .BAT, .Bat, etc.). This vulnerability is fixed in 2.5.6.
References
https://github.com/denoland/deno/releases/tag/v2.5.6
https://github.com/denoland/deno/security/advisories/GHSA-m3c4-prhw-mrx6
CVSS impact metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1 · High
Information
Source identifier
Vulnerability status
Analyzed
Published
2026-01-15T23:15:51.937Z
1 month agoLast modified
2026-01-21T14:32:39.837Z
1 month ago