CVE-2025-66202

Published Dec 9, 2025

Last updated 3 months ago

Overview

Description
Astro is a web framework. Versions 5.15.7 and below have a double URL encoding bypass which allows any unauthenticated attacker to bypass path-based authentication checks in Astro middleware, granting unauthorized access to protected routes. While the original CVE-2025-64765 was fixed in v5.15.8, the fix is insufficient as it only decodes once. By using double-encoded URLs, attackers can still bypass authentication and access any route protected by middleware pathname checks. This issue is fixed in version 5.15.8.
Source
security-advisories@github.com
NVD status
Analyzed
Products
astro

Risk scores

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
2.5
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-647

Social media

Hype score
Not currently trending

Configurations