What is CVE-2025-66202?

CVE-2025-66202 is a medium-severity vulnerability in Withastro Astro, classified under CWE-647. CVSS score: 6.5/10. Published 2025-12-08.

How severe is CVE-2025-66202?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Withastro Astro

CVE-2025-66202

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 route…

EPSS: 0.003 (53.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Withastro Astro — versions < 5.15.8

Weakness classification (CWE)

CWE-647

References

https://github.com/withastro/astro/security/advisories/GHSA-whqg-ppgf-wp8c (x_refsource_CONFIRM)
https://github.com/withastro/astro/security/advisories/GHSA-ggxq-hp9w-j794 (x_refsource_MISC)
https://github.com/withastro/astro/commit/6f800813516b07bbe12c666a92937525fddb58ce (x_refsource_MISC)

Frequently asked questions

What is CVE-2025-66202?: CVE-2025-66202 is a medium-severity vulnerability in Withastro Astro, classified under CWE-647. CVSS score: 6.5/10. Published 2025-12-08.
How severe is CVE-2025-66202?: Medium severity. CVSS v3 base score is 6.5 out of 10.