GHSA-72c6-fx6q-fr5w

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Source
https://github.com/advisories/GHSA-72c6-fx6q-fr5w
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-72c6-fx6q-fr5w/GHSA-72c6-fx6q-fr5w.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-72c6-fx6q-fr5w
Aliases
  • CVE-2026-6270
Published
2026-04-16T22:29:04Z
Modified
2026-04-16T22:51:47.687201Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
@fastify/middie vulnerable to middleware authentication bypass in child plugin scopes
Details

Impact

@fastify/middie v9.3.1 and earlier incorrectly re-prefixes middleware paths when propagating them to child plugin scopes. When a child plugin is registered with a prefix that overlaps with a parent-scoped middleware path, the middleware path is modified during inheritance and silently fails to match incoming requests.

This results in complete bypass of middleware security controls for all routes defined within affected child plugin scopes, including nested (grandchild) scopes. Authentication, authorization, rate limiting, and any other middleware-based security mechanisms are skipped. No special request crafting or configuration is required.

This is the same vulnerability class as GHSA-hrwm-hgmj-7p9c (CVE-2026-33807) in @fastify/express.

Patches

Upgrade to @fastify/middie v9.3.2 or later.

Workarounds

None. Upgrade to the patched version.

Database specific
{
    "github_reviewed_at": "2026-04-16T22:29:04Z",
    "nvd_published_at": "2026-04-16T14:16:19Z",
    "cwe_ids": [
        "CWE-436"
    ],
    "severity": "CRITICAL",
    "github_reviewed": true
}
References

Affected packages

npm / @fastify/middie

Package

Name
@fastify/middie
View open source insights on deps.dev
Purl
pkg:npm/%40fastify/middie

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
9.3.2

Database specific

last_known_affected_version_range
"<= 9.3.1"
source
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-72c6-fx6q-fr5w/GHSA-72c6-fx6q-fr5w.json"