CVE-2026-33807

Published: Apr 15, 2026 Last Modified: Apr 15, 2026
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 9,1
Source: ce714d77-add3-4f53-aff5-83d477b104bb
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: none

Description

AI Translation Available

@fastify/express v4.0.4 and earlier contains a path handling bug in the onRegister function that causes middleware paths to be doubled when inherited by child plugins. When a child plugin is registered with a prefix that matches a middleware path, the middleware path is prefixed a second time, causing it to never match incoming requests. This results in complete bypass of Express middleware security controls, including authentication, authorization, and rate limiting, for all routes defined within affected child plugin scopes. No special configuration or request crafting is required.

Upgrade to @fastify/express v4.0.5 or later.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0005
Percentile
0,2th
Updated

EPSS Score Trend (Last 2 Days)

436

Interpretation Conflict

Incomplete
Common Consequences
Security Scopes Affected:
Integrity Other
Potential Impacts:
Unexpected State Varies By Context
Applicable Platforms
All platforms may be affected
View CWE Details
https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7…
https://cna.openjsf.org/security-advisories.html
https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7…