High
Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass
Type: advisorySources: OSV
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-22864
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 16:29 UTC · Revision 1
Source evidence
Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass
core-osv · Original sourcePublished 15 Jan 2026, 22:58 UTC
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.
osv:CVE-2026-22864
Complete source record
{
"id": "e9457bf32a9471dbcc3cb5531f079f9a9f56fe7b4e4313e2a018a8042da6ed70",
"url": "https://osv.dev/vulnerability/CVE-2026-22864",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Deno has an incomplete fix for command-injection prevention on Windows — case-insensitive extension bypass",
"summary": "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.",
"evidence": "osv:CVE-2026-22864",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-22864",
"aliases": [
"CVE-2026-22864",
"GHSA-m3c4-prhw-mrx6"
],
"metrics": [
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"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
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"affected": [
{
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{
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"source": "AFFECTED_FIELD",
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{
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}
}
],
"modified": "2026-10-28T02:30:30.402118851Z",
"provider": "osv",
"references": [
"https://github.com/denoland/deno/releases/tag/v2.5.6",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22864.json",
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"https://nvd.nist.gov/vuln/detail/CVE-2026-22864"
],
"provider_metadata": {
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],
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"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22864.json"
}
},
"related_cves": [
{
"value": "CVE-2026-22864",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 497361,
"published_at": "2026-01-15T22:58:52.463+00:00"
}