CVE-2026-22864 HIGH

CVE-2026-22864: Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass

Vendor Denoland
Product deno
Weakness CWE-77
Published January 15, 2026
Last update January 16, 2026
View on NVD All CVEs

CVSS base score

8.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 15, 2026 CVE published
January 16, 2026 Record updated