@fastify/middie vulnerable to path-scoped middleware bypass via scope prefix mismatch
CVSS score
9.1
EPSS probability
—
Risk score
0.9
Published
7 h ago
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Impact on My Inventory
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Vulnerability description
DayBreach AI Explanation
Verified against sourcesSources read
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Source agreement
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Evidence confidence
%55
Short explanation
A mismatch in @fastify/middie can lead to the bypass of path-scoped middlewares such as authentication or authorization.
This critical vulnerability allows unauthenticated requests to bypass security checks and reach sensitive route handlers.
What should be done?
- Upgrade to @fastify/middie version 9.3.6 or later
- Enforce authorization in a Fastify hook such as preHandler as a workaround
Chain of evidence and sources
@fastify/middie 9.0.0 ile 9.3.5 sürümleri arasında yol kapsamlı ara yazılım atlama zafiyeti bulunmaktadır.
Uyuşmazlık durumunda kimlik doğrulama veya yetkilendirme gibi ara yazılımlar sessizce atlanabilir.
Show the technical text from the sources
@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.
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE: CWE-436
This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-112712 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | @fastify/middie | @fastify/middie | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 9.1 | CVSS V3_1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | CVE CNA |
| 9.1 | CVSS V31 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-112712 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-112712 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
CVSS Vector Radar Chart
9.1 / 10Vulnerability Scoring Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NYama durumu bilinmiyor
Weakness Type (CWE & CAPEC)
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