CVE-2026-75975 (GCVE-0-2026-75975)
Vulnerability from cvelistv5
Published
2026-08-24 09:58
Modified
2026-08-24 14:30
Severity ?
VLAI Severity ?
EPSS score ?
Summary
fast-uri is a URI parser for Node.js. Its custom parser for bracketed IPv6 literals does not validate the complete IPv6 grammar, so invalid trailing text in an authority can be silently discarded and a malformed attacker-controlled host is turned into a different valid IPv6 destination. For example, a bracketed literal with invalid trailing characters is normalized to the unspecified address, which a Node HTTP client then connects to a local service over loopback, and other malformed literals collapse to private-range addresses. No error is set on the parsed result, so an application checking the error field cannot detect the rewrite. An application that normalizes untrusted URLs before outbound requests, redirects, proxy routing, or address-policy enforcement can be redirected to a local or private IPv6 target, giving a server-side request forgery and address-policy bypass primitive. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 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 validate bracketed IP literals against the full grammar and mark malformed literals as authority errors. Users should upgrade to a patched version.
References
Impacted products
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-75975",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-24T14:29:55.795156Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-24T14:30:09.105Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"packageURL": "pkg:npm/fast-uri",
"product": "fast-uri",
"vendor": "fast-uri",
"versions": [
{
"lessThan": "2.4.5",
"status": "affected",
"version": "2.3.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "2.4.5",
"versionType": "semver"
},
{
"lessThan": "3.1.6",
"status": "affected",
"version": "3.0.0",
"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"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "remediation developer",
"value": "mcollina"
},
{
"lang": "en",
"type": "remediation developer",
"value": "UlisesGascon"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "fast-uri is a URI parser for Node.js. Its custom parser for bracketed IPv6 literals does not validate the complete IPv6 grammar, so invalid trailing text in an authority can be silently discarded and a malformed attacker-controlled host is turned into a different valid IPv6 destination. For example, a bracketed literal with invalid trailing characters is normalized to the unspecified address, which a Node HTTP client then connects to a local service over loopback, and other malformed literals collapse to private-range addresses. No error is set on the parsed result, so an application checking the error field cannot detect the rewrite. An application that normalizes untrusted URLs before outbound requests, redirects, proxy routing, or address-policy enforcement can be redirected to a local or private IPv6 target, giving a server-side request forgery and address-policy bypass primitive. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 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 validate bracketed IP literals against the full grammar and mark malformed literals as authority errors. Users should upgrade to a patched version."
}
],
"value": "fast-uri is a URI parser for Node.js. Its custom parser for bracketed IPv6 literals does not validate the complete IPv6 grammar, so invalid trailing text in an authority can be silently discarded and a malformed attacker-controlled host is turned into a different valid IPv6 destination. For example, a bracketed literal with invalid trailing characters is normalized to the unspecified address, which a Node HTTP client then connects to a local service over loopback, and other malformed literals collapse to private-range addresses. No error is set on the parsed result, so an application checking the error field cannot detect the rewrite. An application that normalizes untrusted URLs before outbound requests, redirects, proxy routing, or address-policy enforcement can be redirected to a local or private IPv6 target, giving a server-side request forgery and address-policy bypass primitive. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 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 validate bracketed IP literals against the full grammar and mark malformed literals as authority errors. Users should upgrade to a patched version."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-20",
"description": "CWE-20: Improper Input Validation",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-918",
"description": "CWE-918: Server-Side Request Forgery (SSRF)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-24T09:58:07.698Z",
"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
"shortName": "openjs"
},
"references": [
{
"url": "https://github.com/fastify/fast-uri/security/advisories/GHSA-f65p-4m7j-42xc"
},
{
"url": "https://cna.openjsf.org/security-advisories.html"
}
],
"title": "fast-uri vulnerable to server-side request forgery via malformed IPv6 normalization",
"x_generator": {
"engine": "cve-kit 1.0.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
"assignerShortName": "openjs",
"cveId": "CVE-2026-75975",
"datePublished": "2026-08-24T09:58:07.698Z",
"dateReserved": "2026-08-18T18:09:48.366Z",
"dateUpdated": "2026-08-24T14:30:09.105Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-75975\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-08-24T14:29:55.795156Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-08-24T14:30:03.563Z\"}}], \"cna\": {\"title\": \"fast-uri vulnerable to server-side request forgery via malformed IPv6 normalization\", \"credits\": [{\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"mcollina\"}, {\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"UlisesGascon\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 7.5, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"fast-uri\", \"product\": \"fast-uri\", \"versions\": [{\"status\": \"affected\", \"version\": \"2.3.1\", \"lessThan\": \"2.4.5\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"2.4.5\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"3.0.0\", \"lessThan\": \"3.1.6\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"3.1.6\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"4.0.0\", \"lessThan\": \"4.1.3\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"4.1.3\", \"versionType\": \"semver\"}], \"packageURL\": \"pkg:npm/fast-uri\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://github.com/fastify/fast-uri/security/advisories/GHSA-f65p-4m7j-42xc\"}, {\"url\": \"https://cna.openjsf.org/security-advisories.html\"}], \"x_generator\": {\"engine\": \"cve-kit 1.0.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"fast-uri is a URI parser for Node.js. Its custom parser for bracketed IPv6 literals does not validate the complete IPv6 grammar, so invalid trailing text in an authority can be silently discarded and a malformed attacker-controlled host is turned into a different valid IPv6 destination. For example, a bracketed literal with invalid trailing characters is normalized to the unspecified address, which a Node HTTP client then connects to a local service over loopback, and other malformed literals collapse to private-range addresses. No error is set on the parsed result, so an application checking the error field cannot detect the rewrite. An application that normalizes untrusted URLs before outbound requests, redirects, proxy routing, or address-policy enforcement can be redirected to a local or private IPv6 target, giving a server-side request forgery and address-policy bypass primitive. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 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 validate bracketed IP literals against the full grammar and mark malformed literals as authority errors. Users should upgrade to a patched version.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"fast-uri is a URI parser for Node.js. Its custom parser for bracketed IPv6 literals does not validate the complete IPv6 grammar, so invalid trailing text in an authority can be silently discarded and a malformed attacker-controlled host is turned into a different valid IPv6 destination. For example, a bracketed literal with invalid trailing characters is normalized to the unspecified address, which a Node HTTP client then connects to a local service over loopback, and other malformed literals collapse to private-range addresses. No error is set on the parsed result, so an application checking the error field cannot detect the rewrite. An application that normalizes untrusted URLs before outbound requests, redirects, proxy routing, or address-policy enforcement can be redirected to a local or private IPv6 target, giving a server-side request forgery and address-policy bypass primitive. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 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 validate bracketed IP literals against the full grammar and mark malformed literals as authority errors. Users should upgrade to a patched version.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-20\", \"description\": \"CWE-20: Improper Input Validation\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-918\", \"description\": \"CWE-918: Server-Side Request Forgery (SSRF)\"}]}], \"providerMetadata\": {\"orgId\": \"ce714d77-add3-4f53-aff5-83d477b104bb\", \"shortName\": \"openjs\", \"dateUpdated\": \"2026-08-24T09:58:07.698Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-75975\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-24T14:30:09.105Z\", \"dateReserved\": \"2026-08-18T18:09:48.366Z\", \"assignerOrgId\": \"ce714d77-add3-4f53-aff5-83d477b104bb\", \"datePublished\": \"2026-08-24T09:58:07.698Z\", \"assignerShortName\": \"openjs\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…