CVE Explorer
CVE-2026-22031
@fastify/middie is the plugin that adds middleware support on steroids to Fastify. A security vulnerability exists in @fastify/middie prior to version 9.1.0 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters (e.g., `/%61dmin` instead of `/admin`). While the middleware engine fails to match the encoded path and skips execution, the underlying Fastify router correctly decodes the path and matches the route handler, allowing attackers to access prot
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"middie","vendor":"fastify","versions":[{"status":"affected","version":"< 9.1.0"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":8.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-177","description":"CWE-177: Improper Handling of URL Encoding (Hex Encoding)","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/problemTypes/0/descriptions/0
Source references
4 source assertions{"name":"https://github.com/fastify/middie/commit/d44cd56eb724490babf7b452fdbbdd37ea2effba","tags":["x_refsource_MISC"],"url":"https://github.com/fastify/middie/commit/d44cd56eb724490babf7b452fdbbdd37ea2effba"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/references/2
{"name":"https://github.com/fastify/middie/pull/245","tags":["x_refsource_MISC"],"url":"https://github.com/fastify/middie/pull/245"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/references/1
{"name":"https://github.com/fastify/middie/releases/tag/v9.1.0","tags":["x_refsource_MISC"],"url":"https://github.com/fastify/middie/releases/tag/v9.1.0"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/references/3
{"name":"https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p","tags":["x_refsource_CONFIRM"],"url":"https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:45ffccee04acfdf105639d06742466e096592d8f614ef542917a0686d78a5eda · sha256:0c09de653829d666… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.