What’s Vulnerable › Vulnerabilities

CVE-2026-114128: Astro: Reflected/Stored XSS via unescaped <script>/<style> tag content in JSX/MDX rendering

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-21 · updated 2026-10-23
• Weakness: CWE-79

Description

Astro is a web framework for content-driven websites. Prior to 7.3.2, Astro's JSX and MDX rendering pipeline treats string children of script and style elements as trusted HTML without distinguishing compiler-generated literal content from dynamic expression values. An application that passes attacker-controlled data directly as a dynamic child can allow a value containing a closing script or style tag to terminate the element and inject arbitrary HTML and JavaScript. Other JSX expression contexts escape dynamic strings automatically; the issue is limited to script and style children rendered through the astro:jsx renderer, including MDX components. Successful exploitation can produce reflected or stored cross-site scripting under the application's origin. This issue is fixed in 7.3.2.

Affected products

• withastro astro: before 7.3.2

References

• https://github.com/withastro/astro/commit/a548223607b9bb146d5d90ddda495343f9a2a739
• https://github.com/withastro/astro/pull/17896
• https://github.com/withastro/astro/releases/tag/astro@7.3.2
• https://github.com/withastro/astro/security/advisories/GHSA-98hj-9722-w3j8

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