by Kastro
Paper/Archive/CVE-2026-22864

CVE-2026-22864

denoland deno — Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass

EPSS 0.7%CVSS 9.8
critical.is priorityof 100
40
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 52.1.521 × 2010.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
deno< 2.5.6–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub_M (CNA)8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/denoland/deno/security/advisories/GHSA-m3c4-prhw-mrx6refgithub.com/denoland/deno/releases/tag/v2.5.6