Astro's bypass of image proxy domain validation leads to SSRF and potential XSS

Description

This is a patch bypass of CVE-2025-58179 in commit 9ecf359. The fix blocks http://, https:// and //, but can be bypassed using backslashes (\) - the endpoint still issues a server-side fetch.

Recommendation

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

• Affected version(s): >= 5.13.4, < 5.13.10
• Patched version(s): 5.13.10

References

• GHSA-qcpr-679q-rhm2
• CVE-2025-59837
• CWE-79
• CWE-918
• CAPEC-310
• OWASP 2021-A10
• OWASP 2021-A3
• OWASP 2021-A6

Related Issues

• tarteaucitron.js has Regular Expression Denial of Service (ReDoS) vulnerability - CVE-2026-22809
• Astro has an Authentication Bypass via Double URL Encoding, a bypass for CVE-2025-64765 - CVE-2025-66202
• Astro Cloudflare adapter has Stored Cross-site Scripting vulnerability in /_image endpoint - CVE-2025-65019
• Astro's middleware authentication checks based on url.pathname can be bypassed via url encoded values - CVE-2025-64765

Tags:

npm

astro