{"id":"CVE-2026-75834","summary":"Grav before 2.0.14 Stored XSS via Invalid UTF-8 Byte","details":"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.","aliases":["GHSA-q2j8-x8hf-63ch"],"modified":"2026-09-10T03:31:06.263533689Z","published":"2026-08-18T11:19:45.094Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75834.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-79"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75834.json"},{"type":"ADVISORY","url":"https://github.com/getgrav/grav/security/advisories/GHSA-q2j8-x8hf-63ch"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75834"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/grav-before-stored-xss-via-invalid-utf-8-byte"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/getgrav/grav","events":[{"introduced":"0"},{"fixed":"5192316f5bf0f033636f43561829d7fc13a4ab64"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"0"},{"fixed":"2.0.14"}]}}],"versions":["2.0.13","2.0.12","2.0.11","2.0.10","2.0.9","2.0.8","2.0.7","2.0.6","2.0.5","2.0.4","2.0.3","2.0.2","2.0.1","1.7.53","1.7.52","1.7.51","1.7.39.1","1.7.39","1.7.38","1.7.37.1","1.7.37","1.7.36","1.7.35","1.7.34","1.7.33","1.7.32","1.7.31","1.7.30","1.7.29.1","1.7.29","1.7.28","1.7.27.1","1.7.27","1.7.26.1","1.7.26","1.7.25","1.7.24","1.7.23","1.7.22","1.7.21","1.7.20","1.7.19","1.7.18","1.7.17","1.7.16","1.7.15","1.7.14","1.7.13","1.7.12","1.7.10","1.7.9","1.7.8","1.7.7","1.7.6","1.7.5","1.7.4","1.7.3","1.7.1","1.7.0","1.7.0-rc.20","1.7.0-rc.19","1.7.0-rc.18","1.7.0-rc.17","1.7.0-rc.15","1.7.0-rc.14","1.7.0-rc.13","1.7.0-rc.12","1.7.0-rc.10","1.7.0-rc.9","1.7.0-rc.8","1.7.0-rc.7","1.7.0-rc.6","1.7.0-rc.5","1.7.0-rc.4","1.7.0-rc.3","1.7.0-rc.2","1.7.0-rc.1","1.7.0-beta.10","1.7.0-beta.9","1.7.0-beta.8","1.7.0-beta.7","1.7.0-beta.6","1.7.0-beta.5","1.7.0-beta.4","1.7.0-beta.3","1.7.0-beta.2","1.7.0-beta.1","1.6.0-rc.4","1.6.0-rc.3","1.6.0-rc.2","1.6.0-rc.1","1.6.0-beta.8","1.6.0-beta.7","1.6.0-beta.6","1.6.0-beta.5","1.6.0-beta.2","1.6.0-beta.1","1.5.0-rc.1","1.5.0-beta.2","1.5.0-beta.1","1.3.0-rc.5","1.3.0-rc.4","1.3.0-rc.3","1.3.0-rc.1","1.2.0-rc.3","1.2.0-rc.2","1.2.0-rc.1","1.1.9-rc.3","1.1.9-rc.2","1.1.9-rc.1","1.1.0-rc.3","1.1.0-rc.2","1.1.0-rc.1","1.1.0-beta.5","1.1.0-beta.4","1.1.0-beta.3","1.1.0-beta.2","1.1.0-beta.1","0.9.19","0.9.18","0.9.17","0.9.16","0.9.15","0.9.14","0.9.13","0.9.12","0.9.11","0.9.10","0.9.9","0.9.8","0.9.7","0.9.6","0.9.5","0.9.4","0.9.3","0.9.2","0.9.0","0.8.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-75834.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"}]}