CVE-2025-66202

medium

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.

References

https://github.com/withastro/astro/security/advisories/GHSA-whqg-ppgf-wp8c

https://github.com/withastro/astro/security/advisories/GHSA-ggxq-hp9w-j794

https://github.com/withastro/astro/commit/6f800813516b07bbe12c666a92937525fddb58ce

Details

Source: Mitre, NVD

Published: 2025-12-09

Updated: 2025-12-10

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00174