CVE-2026-41591
Medium · 6.4CVSS
6.4
EPSS
0.3%
Published
May 8, 2026
CISA due date
—
The record
Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a <script> or <style> tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker able to place input inside a <script> or <style> block could break out of the tag with </SCRIPT>, </Style>, etc. and inject arbitrary HTML/JavaScript, resulting in cross-site scripting. This issue has been patched in marko version 5.38.36 and @marko/runtime-tags 6.0.164.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| npm | @marko/runtime-tags | 0 | 6.0.164 |
| npm | marko | 0 | 5.38.36 |
Related vulnerabilities
- GHSA-x9fj-57fh-c8wq Marko: XSS via case-insensitive script/style closing tag bypass in runtime HTML escaping Same vulnerability
- CVE-2026-96379 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96382 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96368 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96361 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96362 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96360 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96357 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79