CVE-2025-64764: Astro vulnerable to reflected XSS via the server islands feature
Affects astroSource GCVE Database
Not known to be exploited · public detection template (Nuclei) · CVSS 7.1 High : upgrade to 5.15.8 soon.
Data as of 13 Nov 2026, 20:39 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.1 |
|---|
- Patch
- Available – fixed in 5.15.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Nov 2025
Detectable: evidence found.
nuclei template: Astro - Reflected XSS via server islands feature
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade astro to 5.15.8.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmastro | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available in Astro version 5.15.8 that fixes this vulnerability. Users should upgrade to version 5.15.8 or later to remediate the issue. No additional mitigations are indicated by the vendor advisory.
Description
A reflected cross-site scripting (XSS) vulnerability exists in Astro versions prior to 5.15.8 when using the server islands feature. This flaw allows an attacker to inject malicious HTML/JavaScript code via the 's' parameter in requests to the /_server-islands/[name] endpoint, regardless of the component template used. The vulnerability arises because the 'file' value of the 'e' parameter returns the absolute path of the island file, which is sanitized and used as a tag name, while the slot content from 's' is injected as a child, enabling XSS payload execution. A fix is available in version 5.15.8.