VULNERABILITY INTELLIGENCE
CVE-2026-75834
CVSS score5.4 MEDIUM
EPSS probability0.26%
CISA KEVNot currently listed
Published2026-08-18
Last modified2026-10-22
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Description
Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). All XSS detection patterns use the PCRE /u (UTF-8) modifier, so a single invalid UTF-8 byte anywhere in page content causes preg_match() to return false for every pattern, silently bypassing the save-time XSS safety gate (Validation::checkSafety()). An authenticated attacker with page-edit permissions (without the security.xss_whitelist privilege) can store malicious JavaScript that executes in the browser of a visitor who views the affected page.
Weakness classification
- disclosure@vulncheck.com: CWE-79