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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 16 Jan 2026 14:15:00 +0000

Type Values Removed Values Added
First Time appeared Deno
Deno deno
Vendors & Products Deno
Deno deno

Thu, 15 Jan 2026 23:15:00 +0000

Type Values Removed Values Added
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.
Title Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass
Weaknesses CWE-77
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-01-15T22:58:52.463Z

Reserved: 2026-01-12T16:20:16.746Z

Link: CVE-2026-22864

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-01-15T23:15:51.937

Modified: 2026-01-15T23:15:51.937

Link: CVE-2026-22864

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-01-16T13:42:09Z

Weaknesses