CVE-2026-64851: getgrav grav-plugin-shortcode-core Cross-site Scripting

Vulnerability summary

CVE-2026-64851 is a high (CVSS 8.5) Cross-site Scripting vulnerability in getgrav grav-plugin-shortcode-core. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.5% of scored vulnerabilities.

Timeline

1. 19-08-2026
   PublishedVulnerability first disclosed.
2. 19-08-2026
   Last modifiedVulnerability information updated.

Description

Grav Shortcode Core Plugin allows for the development shortcode plugins that utilize the common format utilized by WordPress and BBCode. Prior to 6.2.2, Grav Shortcode Core passes shortcode syntax through Security::detectXss() because it contains no literal less-than character, then ColorShortcode.php and related attribute handlers concatenate an attacker-controlled parameter into HTML without encoding. An account with admin.pages permission can close the generated attribute and add an event handler, creating stored cross-site scripting that executes for visitors or administrators who view the page. This issue is fixed in version 6.2.2.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.