CVE-2026-33807
Essential information
- Published
- 15/04/2026 10:16
- Modified
- 15/04/2026 14:16
- Author
- —
- Creator
- —
- CVSS
- 9.1 CRITICAL (v3.1)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N—
CVSS metrics
- Access vector
- —
- Access complexity
- —
- Authentication
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- NETWORK
- Attack complexity
- LOW
- Privileges required
- NONE
- User interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality impact
- HIGH
- Integrity impact
- HIGH
- Availability impact
- NONE
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
- —
- Attack requirements
- —
- Privileges required
- —
- User interaction
- —
- Confidentiality (V)
- —
- Confidentiality (S)
- —
- Integrity (V)
- —
- Integrity (S)
- —
- Availability (V)
- —
- Availability (S)
- —
- Exploit maturity
- —
Description
@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.
NVD status
- Status
- Received — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- ce714d77-add3-4f53-aff5-83d477b104bb
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| fastify / express | cpe:2.3:a:fastify:express:<4.0.5:*:*:*:*:*:*:* |