What is CVE-2026-50146?

CVE-2026-50146 is a high-severity vulnerability in Astro, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 7.1/10. Published 2026-06-22.

How severe is CVE-2026-50146?

High severity. CVSS v3 base score is 7.1 out of 10.

XSS in Astro

CVE-2026-50146

Astro is a web framework. Prior to 6.3.3, when a component uses a client:* directive, Astro inserts named slot content into a data-astro-template attribute without HTML escaping the slot name allowing an attacker to break out of the attrib…

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N.

Affected products

Astro
Withastro Astro — versions < 6.3.3

Weakness classification (CWE)

CWE-80 — Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-50146?: CVE-2026-50146 is a high-severity vulnerability in Astro, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 7.1/10. Published 2026-06-22.
How severe is CVE-2026-50146?: High severity. CVSS v3 base score is 7.1 out of 10.