CVE-2025-66202
Astro has an Authentication Bypass via Double URL Encoding, a bypass for CVE-2025-64765
- State
- Published
- Severity
- 6.5 Medium
- Published
- Dec 8, 2025
- Updated
- Dec 9, 2025
- Reserved
- Nov 24, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-647 Use of Non-Canonical URL Paths for Authorization Decisions
Affected Products
| Product | Versions |
|---|---|
astrowithastro |
|
References
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