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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-77"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22864.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "2.5.6"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"original_tag": "v2.5.6",
"range": [
{
"fixed": "1b5f3112af364a3327b26f720746819c4f20f20d"
}
],
"source": "REFERENCES_TAG"
},
{
"cpe": "cpe:2.3:a:deno:deno:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.5.6"
}
],
"source": "CPE_RANGE"
}
]
}