Medium severity6.5NVD Advisory· Published Dec 9, 2025· Updated Jun 17, 2026
CVE-2025-66202
CVE-2025-66202
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.
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Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
astronpm | < 5.15.8 | 5.15.8 |
Affected products
3Patches
Vulnerability mechanics
References
6- github.com/withastro/astro/commit/6f800813516b07bbe12c666a92937525fddb58cenvdPatchWEB
- github.com/advisories/GHSA-whqg-ppgf-wp8cghsaADVISORY
- github.com/withastro/astro/security/advisories/GHSA-whqg-ppgf-wp8cnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2025-64765ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2025-66202ghsaADVISORY
- github.com/withastro/astro/security/advisories/GHSA-ggxq-hp9w-j794nvdNot ApplicableWEB
News mentions
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