Astro development server error page is vulnerable to reflected Cross-site Scripting

Description

A Reflected Cross-Site Scripting (XSS) vulnerability exists in Astro’s development server error pages when the trailingSlash configuration option is used. An attacker can inject arbitrary JavaScript code that executes in the victim’s browser context by crafting a malicious URL.

Recommendation

Update the astro package to the latest compatible version. Followings are version details:

• Affected version(s): >= 5.2.0, < 5.15.6
• Patched version(s): 5.15.6

References

• GHSA-w2vj-39qv-7vh7
• CVE-2025-64745
• CWE-79
• CAPEC-310
• OWASP 2021-A3
• OWASP 2021-A6

Related Issues

• Astro Cloudflare adapter has Stored Cross-site Scripting vulnerability in /_image endpoint - CVE-2025-65019
• Astro allows unauthorized third-party images in _image endpoint - CVE-2025-55303
• Astros's duplicate trailing slash feature leads to an open redirection security issue - CVE-2025-54793
• Astro's server source code is exposed to the public if sourcemaps are enabled - CVE-2024-56159

Tags:

npm

astro