CVE-2025-64764: withastro astro · Basic XSS
Affects withastro astroSource CVE Database V5
Not known to be exploited · public detection template (Nuclei) · CVSS 7.1 High : upgrade to 5.15.8 soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- 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
Weaponised: 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 26 Oct 2026.
What to do
Upgrade withastro astro to 5.15.8.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
npmastropkg:npm/astroOther threats | 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
- Upgrade all Astro framework instances to version 5.15.8 or later immediately to apply the official patch that fixes the XSS vulnerability.
- Conduct a thorough audit of all web applications using Astro, focusing on those employing the server islands feature, to identify any instances of reflected user input in responses.
- Implement additional input validation and output encoding layers at the application level to sanitize user-supplied data, especially in URL parameters and form inputs.
- Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks.
- Educate development teams on secure coding practices related to client-side rendering and hydration features to prevent similar issues.
- Monitor web traffic and logs for unusual patterns indicative of attempted XSS exploitation, such as suspicious query strings or script injection attempts.
- Inform users and stakeholders about the vulnerability and encourage caution with unsolicited links until mitigations are in place.
- Consider implementing Web Application Firewalls (WAF) with rules targeting reflected XSS patterns as an additional protective measure.
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.