{"id":"CVE-2026-75834","title":"Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php)","summary":"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 b…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"vendor":"getgrav","product":"grav","affected":["grav < 2.0.14"],"patched":["getgrav/grav 2.0.14"],"published":"2026-08-18","updated":"2026-10-08","sourceUpdated":"2026-10-08T16:17:41.073","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-75834","references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-q2j8-x8hf-63ch","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/grav-before-stored-xss-via-invalid-utf-8-byte","label":"disclosure@vulncheck.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75834"},{"url":"https://github.com/advisories/GHSA-q2j8-x8hf-63ch"}],"tags":["nvd","cve.org","ghsa","composer"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-08-18T12:51:15.491121Z"},"epss":0.00255,"epssPercentile":0.1697,"aliases":["GHSA-q2j8-x8hf-63ch"],"ecosystem":"composer","ingestedAt":"2026-09-08T21:11:12.280Z","slug":"CVE-2026-75834","body":"## Overview\n\nGrav 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-75834)\n\nAffected packages:\n\n- `getgrav/grav < 2.0.14`\n\nPatched in:\n\n- `getgrav/grav 2.0.14`\n\nSource: https://github.com/advisories/GHSA-q2j8-x8hf-63ch","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}