CVE-2025-64764: Astro vulnerable to reflected XSS via the server islands feature

November 19, 2025

After some research it appears that it is possible to obtain a reflected XSS when the server islands feature is used in the targeted application, regardless of what was intended by the component template(s).

References

github.com/advisories/GHSA-wrwg-2hg8-v723
github.com/withastro/astro
github.com/withastro/astro/commit/790d9425f39bbbb462f1c27615781cd965009f91
github.com/withastro/astro/security/advisories/GHSA-wrwg-2hg8-v723
nvd.nist.gov/vuln/detail/CVE-2025-64764

Code Behaviors & Features

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