CVE-2025-64764 Astro is vulnerable to Reflected XSS via the server islands feature
Attackers can execute arbitrary scripts in user browsers via reflected XSS in Astro's server islands feature, requiring the feature to be enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-64764?
CVE-2025-64764 is a high-severity cross-site scripting vulnerability in withastro astro, published on 19 Nov 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Astro is a web framework. Prior to version 5.15.8, a reflected XSS vulnerability is present when the server islands feature is used in the targeted application, regardless of what was intended by the component template(s). This issue has been patched in version 5.15.8.
Weakness: CWE-80
Which versions are affected by CVE-2025-64764?
2 open source packages ship an affected version, including astro. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
astro npm | All versions | 5.15.8 |
astro npm | All versions | 5.15.8 |
Products include Astro Astro.
How do I fix CVE-2025-64764?
Upgrade astro to 5.15.8 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-64764 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-64764 exists.
Public exploit code: 1 Nuclei template.
Other vulnerabilities in withastro astro
- CVE-2024-56159 Server source code is exposed to the public if sourcemaps are enabled
- CVE-2026-54299 Astro: Host header SSRF in prerendered error page fetch
- CVE-2025-59837 astro allows bypass of image proxy domain validation leading to SSRF and potential XSS
- CVE-2026-50146 Astro: Reflected XSS via unescaped slot name
- CVE-2025-64765 Astro middleware authentication checks based on url.pathname can be bypassed via url encoded values
Sources
Also known as GHSA-wrwg-2hg8-v723.