Medium severity · published Oct 21, 2026
CVE-2026-114128
Astro: Reflected/Stored XSS via unescaped <script>/<style> tag content in JSX/MDX rendering
New
6.5
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
astro · withastro
< 7.3.2 · source: vendor
Affected product
AS
astro
withastro
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