CVE-2025-64765 is a path traversal vulnerability classified under CWE-22 affecting the Astro web framework versions prior to 5.15.8. Astro internally uses decodeURI() to normalize request paths for routing and rendering decisions, but its middleware components read the request path from context.url.pathname without applying the same normalization. This discrepancy creates a security gap where attackers can craft encoded path variants that Astro's router will decode and accept as valid routes, while middleware validation checks fail to recognize these variants as protected paths. Consequently, attackers can bypass access controls and reach restricted routes or resources that should be protected. The vulnerability does not require authentication, user interaction, or privileges, and can be exploited remotely over the network. Although no known exploits are currently reported in the wild, the issue poses a risk of unauthorized access to sensitive application endpoints or data. The vulnerability was publicly disclosed and patched in Astro version 5.15.8, which ensures consistent path normalization between routing and middleware validation. The CVSS 4.0 base score is 6.9, indicating a medium severity level due to the ease of exploitation and potential confidentiality impact, though integrity and availability impacts are not evident. This vulnerability highlights the importance of consistent input normalization across all components handling request paths in web frameworks.

For European organizations, this vulnerability could lead to unauthorized access to protected web application routes, potentially exposing sensitive data or internal functionality. Organizations relying on Astro for web development, especially those with complex middleware validation logic, may inadvertently allow attackers to bypass security controls. This could result in data breaches, unauthorized operations, or further exploitation chains if sensitive administrative or internal APIs are exposed. The impact is particularly relevant for sectors with stringent data protection requirements such as finance, healthcare, and government services. Additionally, organizations with public-facing web applications using vulnerable Astro versions may face reputational damage and regulatory consequences under GDPR if personal data is compromised. The lack of required authentication and user interaction increases the risk of automated exploitation attempts. However, since the vulnerability affects only versions prior to 5.15.8 and requires specific middleware misconfigurations, the overall impact depends on the deployment context and patching status.

The primary mitigation is to upgrade all Astro framework instances to version 5.15.8 or later, where the path normalization inconsistency is resolved. Organizations should audit their web applications to identify any use of vulnerable Astro versions and prioritize patching. Additionally, developers should review middleware code to ensure that path validation uses the same normalization methods as the routing logic, ideally applying decodeURI() or equivalent consistently before access control checks. Implementing strict input validation and canonicalization for all request paths can reduce the risk of path traversal attacks. Web application firewalls (WAFs) can be configured to detect and block suspicious encoded path variants that attempt to bypass access controls. Security teams should monitor for unusual access patterns to protected routes and conduct penetration testing focused on path traversal vectors. Finally, maintaining an inventory of web frameworks and dependencies with timely updates is essential to prevent exploitation of similar issues.