CVE-2026-22864 — Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass
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 pat…
Published: 2026-01-15 · CVSS: 8.1 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7