Is this vulnerability remotely exploitable?

Yes. Any attacker with network access to the application can attempt to craft request paths that exploit the mismatch between router normalization and middleware path matching.

Does an attacker need valid credentials to exploit this?

Typically no. The vulnerability specifically affects authentication/authorization middleware, so an unauthenticated attacker may be able to reach endpoints that are intended to be protected.

What is the safest general fix pattern?

Move critical authentication and authorization checks into Fastify's route-level mechanisms (such as `onRequest` or `preHandler` hooks) or other centralized guard layers that see the same normalized path as the router, and ensure all security checks are based on a canonical request representation.

Severity:

CRITICAL RISK

(9.1)

Input Validation Flaw (CWE-20) in @fastify/middie Path-Scoped Middleware

CVE-2026-2880

Published:

Feb 27, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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HIGH RISK

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Unauthorized Access to Internal Resources via SSRF

May 6, 2026

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HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Privilege Escalation via Bypassed Access Control

May 6, 2026

Vulnerability Type

Category:

Input Validation / Routing Normalization Mismatch

CWE:

CWE-20

Impact:

Authentication and Authorization Bypass

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Input Validation / Routing Normalization Mismatch

CWE:

CWE-20

Impact:

Authentication and Authorization Bypass

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

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Input Validation Flaw (CWE-20) in @fastify/middie Path-Scoped Middleware

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.6)

Server-Side Request Forgery (CWE-918) in OpenClaw Zalo Plugin sendPhoto

HIGH RISK

HIGH

(8.8)

Authorization Bypass (CWE-863) in OpenClaw Matrix Room Control Commands

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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