CVE-2026-50146 - Vulnerability Details - OpenCVE

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 attribute context and inject arbitrary HTML, resulting in reflected XSS during SSR. This vulnerability is fixed in 6.3.3.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact High

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation poc

Automatable no

Technical Impact partial

Vendors	Products
Withastro	Astro

No data.

No data.

References

Link	Providers
https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp

History

Tue, 23 Jun 2026 14:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Mon, 22 Jun 2026 21:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Withastro Withastro astro
Vendors & Products		Withastro Withastro astro

Mon, 22 Jun 2026 18:45:00 +0000

Type	Values Removed	Values Added
Description		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 attribute context and inject arbitrary HTML, resulting in reflected XSS during SSR. This vulnerability is fixed in 6.3.3.
Title		Astro: Reflected XSS via unescaped slot name
Weaknesses		CWE-80
References		https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp
Metrics		cvssV3_1 `{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N'}`

MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-06-22T17:31:56.313Z

Updated: 2026-06-23T14:11:04.510Z

Reserved: 2026-06-03T18:49:32.276Z

Link: CVE-2026-50146

Vulnrichment

Updated: 2026-06-23T14:10:51.229Z

NVD

No data.

Redhat

No data.

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