CVE-2026-53779
Full vulnerability record from the local CVENow database.
Description
WebP Server Go through 0.14.4 contains a path traversal vulnerability on Windows that allows unauthenticated attackers to read files outside the configured IMG_PATH directory by sending requests with percent-encoded backslashes (%5C) that bypass the path.Clean() sanitization in handler/router.go. Attackers can exploit the discrepancy between Go's forward-slash-only path normalization and Windows file system APIs that treat backslashes and forward slashes as equivalent to access arbitrary files on the host filesystem accessible to the server process.
Severity
HIGH
CVSS score
8.7
(v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-06-22 19:17:13.513000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON
{
"id": "CVE-2026-53779",
"sourceIdentifier": "[email protected]",
"published": "2026-06-22T19:17:13.513",
"lastModified": "2026-10-25T23:10:00.167",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "WebP Server Go through 0.14.4 contains a path traversal vulnerability on Windows that allows unauthenticated attackers to read files outside the configured IMG_PATH directory by sending requests with percent-encoded backslashes (%5C) that bypass the path.Clean() sanitization in handler/router.go. Attackers can exploit the discrepancy between Go's forward-slash-only path normalization and Windows file system APIs that treat backslashes and forward slashes as equivalent to access arbitrary files on the host filesystem accessible to the server process."
},
{
"lang": "es",
"value": "WebP Server Go hasta la versión 0.14.4 contiene una vulnerabilidad de salto de ruta en Windows que permite a atacantes no autenticados leer archivos fuera del directorio IMG_PATH configurado enviando solicitudes con barras invertidas codificadas en porcentaje (%5C) que eluden la sanitización path.Clean() en handler/router.go. Los atacantes pueden explotar la discrepancia entre la normalización de rutas de Go, que solo usa barras diagonales, y las API del sistema de archivos de Windows que tratan las barras invertidas y las barras diagonales como equivalentes para acceder a archivos arbitrarios en el sistema de archivos del host accesibles para el proceso del servidor."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "webp-sh",
"product": "webp_server_go",
"defaultStatus": "affected",
"repo": "https://github.com/webp-sh/webp_server_go",
"packageURL": "pkg:github/webp-sh/webp_server_go",
"versions": [
{
"version": "0",
"lessThan": "0.15.0",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-06-23T14:12:03.904360Z",
"id": "CVE-2026-53779",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-22"
}
]
}
],
"references": [
{
"url": "https://github.com/webp-sh/webp_server_go/commit/eb3b5f9289b331cb639cd610b0d1c532d2cc24e0",
"source": "[email protected]"
},
{
"url": "https://github.com/webp-sh/webp_server_go/pull/451",
"source": "[email protected]"
},
{
"url": "https://www.vulncheck.com/advisories/webp-server-go-path-traversal-via-backslash-encoding-on-windows",
"source": "[email protected]"
}
]
}