CVE-2025-66202
MEDIUM EPSS 19.1%
Published Dec 9, 20256mo ago · Modified Jun 17, 20262w ago
6.5 CVSS 3.1
Published Dec 9, 2025 6mo ago
Last Modified Jun 17, 2026 2w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Low
Integrity Low
Availability None
Threat Intelligence
EPSS Exploit Probability
19.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available
Weaknesses 1
CWE-647
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| astro | astro | * | <5.15.8 |
References 3
- github.com https://github.com/withastro/astro/commit/6f800813516b07bbe12c666a92937525fddb58ce
- github.com https://github.com/withastro/astro/security/advisories/GHSA-ggxq-hp9w-j794
- github.com https://github.com/withastro/astro/security/advisories/GHSA-whqg-ppgf-wp8c
Remediation
- github.com https://github.com/withastro/astro/commit/6f800813516b07bbe12c666a92937525fddb58ce