Answer in brief
CVE-2026-85184 records a Critical severity (CVSS 9.1) vulnerability in @fastify/middie vulnerable to path-scoped middleware bypass via absolute-form request target. The current sources do not mark it as known exploited. The current feed maps @fastify/middie/@fastify/middie (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps @fastify/middie/@fastify/middie (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:fastify:fastify\/middie:*:*:*:*:*:node.js:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| @fastify/middie/@fastify/middiegeneric | >=9.1.0 <9.3.4 | 9.3.4 |
Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 4, 2026
@fastify/middie versions >= 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request using an absolute-form target reaches the route handler while the path-scoped middleware, such as authentication or authorization, is skipped. An unauthenticated network attacker can use this to bypass path-based access controls in a Fastify application that relies on middie for those controls. Users should upgrade to @fastify/middie 9.3.4 or later.
Quoted source text, attributed separately from HOL analysis.