FKIE_CVE-2026-75899
Vulnerability from fkie_nvd - Published: 2026-08-24 10:16 - Updated: 2026-10-14 13:10
Severity
Summary
fast-uri is a URI parser for Node.js. It decodes percent escapes in a hostname during parsing and then decodes the parsed hostname a second time during authority recomposition, so a single call to normalize or resolve can turn nested percent-encoded input into a different network destination such as a loopback hostname or address. For example, a doubly encoded host that spells out a loopback name decodes to that live host in one operation, which contradicts RFC 3986 section 2.4 that an implementation must not decode the same string more than once. An application that normalizes or resolves an untrusted HTTP-family URI before outbound routing, redirect validation, or a host-policy check can receive a destination different from the one the original encoded host represented, giving a server-side request forgery and host-policy bypass primitive. This is an incomplete-fix variant of CVE-2026-6322. The affected versions are 2.4.1 up to but not including 2.4.5, 3.1.2 up to but not including 3.1.6, and 4.0.0 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which normalize percent escapes once and preserve encoded percent signs. Users should upgrade to a patched version.
References
| URL | Tags | ||
|---|---|---|---|
| ce714d77-add3-4f53-aff5-83d477b104bb | https://cna.openjsf.org/security-advisories.html | Vendor Advisory | |
| ce714d77-add3-4f53-aff5-83d477b104bb | https://github.com/fastify/fast-uri/security/advisories/GHSA-fph4-wmhf-6fwf | Mitigation, Vendor Advisory |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"packageURL": "pkg:npm/fast-uri",
"product": "fast-uri",
"vendor": "fast-uri",
"versions": [
{
"lessThan": "2.4.5",
"status": "affected",
"version": "2.4.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "2.4.5",
"versionType": "semver"
},
{
"lessThan": "3.1.6",
"status": "affected",
"version": "3.1.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "3.1.6",
"versionType": "semver"
},
{
"lessThan": "4.1.3",
"status": "affected",
"version": "4.0.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.1.3",
"versionType": "semver"
}
]
}
],
"source": "ce714d77-add3-4f53-aff5-83d477b104bb"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:openjsf:fast-uri:*:*:*:*:*:node.js:*:*",
"matchCriteriaId": "1EDB4E92-09B0-4B21-9FFE-FE199789F86F",
"versionEndExcluding": "2.4.5",
"versionStartIncluding": "2.4.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:openjsf:fast-uri:*:*:*:*:*:node.js:*:*",
"matchCriteriaId": "FE262744-646F-4399-8B26-11C21B3954D5",
"versionEndExcluding": "3.1.6",
"versionStartIncluding": "3.1.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:a:openjsf:fast-uri:*:*:*:*:*:node.js:*:*",
"matchCriteriaId": "E5821EBB-01F8-44C6-8EFF-BA388AB307D5",
"versionEndExcluding": "4.1.3",
"versionStartIncluding": "4.0.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "fast-uri is a URI parser for Node.js. It decodes percent escapes in a hostname during parsing and then decodes the parsed hostname a second time during authority recomposition, so a single call to normalize or resolve can turn nested percent-encoded input into a different network destination such as a loopback hostname or address. For example, a doubly encoded host that spells out a loopback name decodes to that live host in one operation, which contradicts RFC 3986 section 2.4 that an implementation must not decode the same string more than once. An application that normalizes or resolves an untrusted HTTP-family URI before outbound routing, redirect validation, or a host-policy check can receive a destination different from the one the original encoded host represented, giving a server-side request forgery and host-policy bypass primitive. This is an incomplete-fix variant of CVE-2026-6322. The affected versions are 2.4.1 up to but not including 2.4.5, 3.1.2 up to but not including 3.1.6, and 4.0.0 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which normalize percent escapes once and preserve encoded percent signs. Users should upgrade to a patched version."
},
{
"lang": "es",
"value": "fast-uri es un analizador de URI para Node.js. Decodifica los escapes de porcentaje en un nombre de host durante el an\u00e1lisis y luego decodifica el nombre de host analizado una segunda vez durante la recomposici\u00f3n de la autoridad, por lo que una \u00fanica llamada a normalizar o resolver puede convertir una entrada anidada codificada por porcentaje en un destino de red diferente, como un nombre de host o una direcci\u00f3n de bucle invertido. Por ejemplo, un host doblemente codificado que deletrea un nombre de bucle invertido se decodifica a ese host activo en una sola operaci\u00f3n, lo que contradice la secci\u00f3n 2.4 de la RFC 3986 que establece que una implementaci\u00f3n no debe decodificar la misma cadena m\u00e1s de una vez. Una aplicaci\u00f3n que normaliza o resuelve un URI de la familia HTTP no confiable antes del enrutamiento saliente, la validaci\u00f3n de redirecci\u00f3n o una comprobaci\u00f3n de pol\u00edtica de host puede recibir un destino diferente al que representaba el host codificado original, lo que da lugar a una falsificaci\u00f3n de petici\u00f3n del lado del servidor y una primitiva de omisi\u00f3n de pol\u00edtica de host. Esta es una variante de correcci\u00f3n incompleta de CVE-2026-6322. Las versiones afectadas son 2.4.1 hasta, pero sin incluir, 2.4.5, 3.1.2 hasta, pero sin incluir, 3.1.6, y 4.0.0 hasta, pero sin incluir, 4.1.3. El problema est\u00e1 solucionado en 2.4.5, 3.1.6 y 4.1.3, que normalizan los escapes de porcentaje una vez y preservan los signos de porcentaje codificados. Los usuarios deben actualizar a una versi\u00f3n parcheada."
}
],
"id": "CVE-2026-75899",
"lastModified": "2026-10-14T13:10:00.187",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "ce714d77-add3-4f53-aff5-83d477b104bb",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-75899",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-24T16:16:34.392088Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-24T10:16:39.960",
"references": [
{
"source": "ce714d77-add3-4f53-aff5-83d477b104bb",
"tags": [
"Vendor Advisory"
],
"url": "https://cna.openjsf.org/security-advisories.html"
},
{
"source": "ce714d77-add3-4f53-aff5-83d477b104bb",
"tags": [
"Mitigation",
"Vendor Advisory"
],
"url": "https://github.com/fastify/fast-uri/security/advisories/GHSA-fph4-wmhf-6fwf"
}
],
"sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-174"
},
{
"lang": "en",
"value": "CWE-918"
}
],
"source": "ce714d77-add3-4f53-aff5-83d477b104bb",
"type": "Secondary"
}
]
}
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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