GHSA-83W8-P2F5-377R
Vulnerability from github – Published: 2026-07-24 16:43 – Updated: 2026-07-24 16:43Impact
@fastify/static is vulnerable to a bypass of route-based middleware and guards via non-leading .. and %2E%2E path segments. find-my-way does not normalize .. when matching routes, so a request such as /foo/../deep/secret.txt matches the static plugin's catch-all instead of the guarded /deep/*. The getPathnameForSend helper introduced by the fix for GHSA-x428-ghpx-8j92 only guards against the %2F variant; .. and %2E%2E survive the decodeURI + encodeURI round-trip and are then collapsed away by @fastify/send's path.normalize before its own traversal guard runs.
Applications that rely on route-based middleware or guards to protect files served by @fastify/static can be bypassed with non-leading dot-dot path segments.
Patches
Upgrade to @fastify/static 10.1.1.
Workarounds
Do not use route-based middlewares or guards to protect files served by @fastify/static.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 10.1.0"
},
"package": {
"ecosystem": "npm",
"name": "@fastify/static"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "10.1.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-15074"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-24T16:43:21Z",
"nvd_published_at": "2026-07-23T04:16:31Z",
"severity": "HIGH"
},
"details": "### Impact\n\n`@fastify/static` is vulnerable to a bypass of route-based middleware and guards via non-leading `..` and `%2E%2E` path segments. `find-my-way` does not normalize `..` when matching routes, so a request such as `/foo/../deep/secret.txt` matches the static plugin\u0027s catch-all instead of the guarded `/deep/*`. The `getPathnameForSend` helper introduced by the fix for [GHSA-x428-ghpx-8j92](https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92) only guards against the `%2F` variant; `..` and `%2E%2E` survive the `decodeURI` + `encodeURI` round-trip and are then collapsed away by `@fastify/send`\u0027s `path.normalize` before its own traversal guard runs.\n\nApplications that rely on route-based middleware or guards to protect files served by `@fastify/static` can be bypassed with non-leading dot-dot path segments.\n\n### Patches\n\nUpgrade to `@fastify/static` 10.1.1.\n\n### Workarounds\n\nDo not use route-based middlewares or guards to protect files served by `@fastify/static`.",
"id": "GHSA-83w8-p2f5-377r",
"modified": "2026-07-24T16:43:21Z",
"published": "2026-07-24T16:43:21Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/fastify/fastify-static/security/advisories/GHSA-83w8-p2f5-377r"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15074"
},
{
"type": "WEB",
"url": "https://github.com/fastify/fastify-static/commit/db4276f846ba56b21f93768cd6636ee5e2fc58b1"
},
{
"type": "WEB",
"url": "https://cna.openjsf.org/security-advisories.html"
},
{
"type": "PACKAGE",
"url": "https://github.com/fastify/fastify-static"
},
{
"type": "WEB",
"url": "https://github.com/fastify/fastify-static/releases/tag/v10.1.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "@fastify/static vulnerable to route guard bypass via path traversal"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.