CVE-2026-59731 Details
Description
Astro is a web framework for content-driven websites. Version 6.4.7 performs authorization decisions on a partially decoded pathname after reaching the iterative URL decoder limit, while later rewrite route matching performs an additional decodeURI() operation and can resolve the request to a protected route. This issue is fixed in version 6.4.8.
A vulnerability in Astro version 6.4.7 allows for an authorization bypass by exploiting the iterative URL decoding limit. When a request path is encoded more than the maximum decoding iterations, Astro performs authorization checks on a partially decoded pathname. Subsequently, an additional decoding step during route matching converts this into a fully decoded path, potentially leading to unauthorized access on protected routes. This issue arises because middleware and routing logic handle pathnames differently, creating a mismatch that can be exploited under certain conditions.
Users can upgrade to Astro version 6.4.8, which addresses this vulnerability by rejecting over-encoded paths before they can bypass authorization checks.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 8, 2026CISA-ADP
Assessed Jul 9, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/withastro/astro/security/advisories/GHSA-vj59-8hwv-xxmv | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/withastro/astro/commit/27c80ea92248993e5fce94b2c26d87d611ab6785 | [email protected] | Source CodeVendor |
| https://github.com/withastro/astro/pull/17109 | [email protected] | Issue TrackingVendor |
| https://github.com/withastro/astro/releases/tag/[email protected] | [email protected] | Release NotesVendor |
| https://github.com/withastro/astro/security/advisories/GHSA-vj59-8hwv-xxmv | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-647 | Use of Non-Canonical URL Paths for Authorization Decisions | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Astro | 6.4.7 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 9, 2026 | CVE Modified | CISA-ADP |
| Jul 8, 2026 | New CVE Received | [email protected] |