CVE-2026-49421
Full vulnerability record from the local CVENow database.
Description
The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup. The flag was silently dropped, so path resolution was not actually restricted. A process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory. A caller relying on this flag for path containment may delete files outside the intended directory tree.
Severity
HIGH
CVSS score
7.1
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-08-19 06:17:41.160000
Last modified
2026-11-09 20:10:00.200000
View original CVE JSON
{
"id": "CVE-2026-49421",
"sourceIdentifier": "[email protected]",
"published": "2026-08-19T06:17:41.160",
"lastModified": "2026-11-09T20:10:00.200",
"vulnStatus": "Analyzed",
"cveTags": [],
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{
"lang": "en",
"value": "The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup. The flag was silently dropped, so path resolution was not actually restricted.\n\nA process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory. A caller relying on this flag for path containment may delete files outside the intended directory tree."
},
{
"lang": "es",
"value": "La función del kernel que implementa unlinkat(2) y funlinkat(2) validó la bandera AT_RESOLVE_BENEATH pero no logró pasarla a la búsqueda de ruta subyacente. La bandera fue descartada silenciosamente, por lo que la resolución de ruta no estaba realmente restringida.\n\nUn proceso que utiliza AT_RESOLVE_BENEATH con unlinkat(2) o funlinkat(2) para confinar la resolución de ruta puede de hecho resolver rutas por encima del directorio de inicio. Un llamador que confía en esta bandera para la contención de rutas puede eliminar archivos fuera del árbol de directorios previsto."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "FreeBSD",
"product": "FreeBSD",
"defaultStatus": "unknown",
"modules": [
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],
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"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
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"id": "CVE-2026-49421",
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{
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"description": [
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"references": [
{
"url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
}
]
}