CVE-2026-112712 (GCVE-0-2026-112712)
Vulnerability from cvelistv5
Published
2026-10-20 20:43
Modified
2026-10-30 17:17
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-436 - Interpretation Conflict
Summary
@fastify/middie is the Express-style middleware engine for Fastify. In versions from 9.0.0 through 9.3.5, the use() function joined a path-scoped middleware's mount path to the plugin scope prefix in a way that could diverge from the path Fastify's router serves, most often when the scope prefix ended in a slash, and also for array mount paths and for mount paths written without a leading slash. When the two paths disagreed, the middleware was silently skipped while the route handler still ran, so path-scoped middleware such as authentication, authorization, or rate limiting could be bypassed by a single unauthenticated request. The issue is fixed in @fastify/middie 9.3.6, and users should upgrade to 9.3.6 or later. As a workaround, enforce authorization in a Fastify hook such as preHandler that runs after the router has resolved the request.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| @fastify/middie | @fastify/middie |
Version: 9.0.0 ≤ |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-112712",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-30T15:48:29.631546Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-30T17:17:28.727Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"packageURL": "pkg:npm/@fastify/middie",
"product": "@fastify/middie",
"vendor": "@fastify/middie",
"versions": [
{
"lessThan": "9.3.6",
"status": "affected",
"version": "9.0.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "9.3.6",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "reporter",
"value": "zachariah-mithani"
},
{
"lang": "en",
"type": "remediation developer",
"value": "mcollina"
},
{
"lang": "en",
"type": "remediation developer",
"value": "UlisesGascon"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "@fastify/middie is the Express-style middleware engine for Fastify. In versions from 9.0.0 through 9.3.5, the use() function joined a path-scoped middleware\u0027s mount path to the plugin scope prefix in a way that could diverge from the path Fastify\u0027s router serves, most often when the scope prefix ended in a slash, and also for array mount paths and for mount paths written without a leading slash. When the two paths disagreed, the middleware was silently skipped while the route handler still ran, so path-scoped middleware such as authentication, authorization, or rate limiting could be bypassed by a single unauthenticated request. The issue is fixed in @fastify/middie 9.3.6, and users should upgrade to 9.3.6 or later. As a workaround, enforce authorization in a Fastify hook such as preHandler that runs after the router has resolved the request."
}
],
"value": "@fastify/middie is the Express-style middleware engine for Fastify. In versions from 9.0.0 through 9.3.5, the use() function joined a path-scoped middleware\u0027s mount path to the plugin scope prefix in a way that could diverge from the path Fastify\u0027s router serves, most often when the scope prefix ended in a slash, and also for array mount paths and for mount paths written without a leading slash. When the two paths disagreed, the middleware was silently skipped while the route handler still ran, so path-scoped middleware such as authentication, authorization, or rate limiting could be bypassed by a single unauthenticated request. The issue is fixed in @fastify/middie 9.3.6, and users should upgrade to 9.3.6 or later. As a workaround, enforce authorization in a Fastify hook such as preHandler that runs after the router has resolved the request."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.1,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-436",
"description": "CWE-436: Interpretation Conflict",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-20T20:43:48.681Z",
"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
"shortName": "openjs"
},
"references": [
{
"url": "https://github.com/fastify/middie/security/advisories/GHSA-5p92-8765-9fv8"
},
{
"url": "https://cna.openjsf.org/security-advisories.html"
}
],
"title": "@fastify/middie vulnerable to path-scoped middleware bypass via scope prefix mismatch",
"x_generator": {
"engine": "cve-kit 1.0.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
"assignerShortName": "openjs",
"cveId": "CVE-2026-112712",
"datePublished": "2026-10-20T20:43:48.681Z",
"dateReserved": "2026-10-19T17:43:39.048Z",
"dateUpdated": "2026-10-30T17:17:28.727Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"cna\": {\"providerMetadata\": {\"orgId\": \"ce714d77-add3-4f53-aff5-83d477b104bb\", \"shortName\": \"openjs\", \"dateUpdated\": \"2026-10-20T20:43:48.681Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"@fastify/middie is the Express-style middleware engine for Fastify. In versions from 9.0.0 through 9.3.5, the use() function joined a path-scoped middleware\u0027s mount path to the plugin scope prefix in a way that could diverge from the path Fastify\u0027s router serves, most often when the scope prefix ended in a slash, and also for array mount paths and for mount paths written without a leading slash. When the two paths disagreed, the middleware was silently skipped while the route handler still ran, so path-scoped middleware such as authentication, authorization, or rate limiting could be bypassed by a single unauthenticated request. The issue is fixed in @fastify/middie 9.3.6, and users should upgrade to 9.3.6 or later. As a workaround, enforce authorization in a Fastify hook such as preHandler that runs after the router has resolved the request.\", \"supportingMedia\": [{\"type\": \"text/html\", \"base64\": false, \"value\": \"@fastify/middie is the Express-style middleware engine for Fastify. In versions from 9.0.0 through 9.3.5, the use() function joined a path-scoped middleware\u0027s mount path to the plugin scope prefix in a way that could diverge from the path Fastify\u0027s router serves, most often when the scope prefix ended in a slash, and also for array mount paths and for mount paths written without a leading slash. When the two paths disagreed, the middleware was silently skipped while the route handler still ran, so path-scoped middleware such as authentication, authorization, or rate limiting could be bypassed by a single unauthenticated request. The issue is fixed in @fastify/middie 9.3.6, and users should upgrade to 9.3.6 or later. As a workaround, enforce authorization in a Fastify hook such as preHandler that runs after the router has resolved the request.\"}]}], \"affected\": [{\"vendor\": \"@fastify/middie\", \"product\": \"@fastify/middie\", \"defaultStatus\": \"unaffected\", \"versions\": [{\"versionType\": \"semver\", \"status\": \"affected\", \"version\": \"9.0.0\", \"lessThan\": \"9.3.6\"}, {\"versionType\": \"semver\", \"status\": \"unaffected\", \"version\": \"9.3.6\"}], \"packageURL\": \"pkg:npm/@fastify/middie\"}], \"references\": [{\"url\": \"https://github.com/fastify/middie/security/advisories/GHSA-5p92-8765-9fv8\"}, {\"url\": \"https://cna.openjsf.org/security-advisories.html\"}], \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"zachariah-mithani\"}, {\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"mcollina\"}, {\"lang\": \"en\", \"type\": \"remediation developer\", \"value\": \"UlisesGascon\"}], \"title\": \"@fastify/middie vulnerable to path-scoped middleware bypass via scope prefix mismatch\", \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N\", \"baseScore\": 9.1, \"baseSeverity\": \"CRITICAL\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-436\", \"lang\": \"en\", \"description\": \"CWE-436: Interpretation Conflict\", \"type\": \"CWE\"}]}], \"x_generator\": {\"engine\": \"cve-kit 1.0.0\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-112712\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-30T15:48:29.631546Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-30T15:48:30.358Z\"}}]}",
"cveMetadata": "{\"cveId\": \"CVE-2026-112712\", \"assignerOrgId\": \"ce714d77-add3-4f53-aff5-83d477b104bb\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"openjs\", \"dateReserved\": \"2026-10-19T17:43:39.048Z\", \"datePublished\": \"2026-10-20T20:43:48.681Z\", \"dateUpdated\": \"2026-10-30T17:17:28.727Z\"}",
"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…