CVE-2026-75834
Grav before 2.0.14 Stored XSS via Invalid UTF-8 Byte
CVSS Score
5.4
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-79 |
| Vendor | getgrav |
| Product | grav |
| Published | Aug 18, 2026 |
| Last Updated | Aug 18, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
getgrav / grav
0 < 2.0.14
References
Credits
🔍 iaohkut-from-NightWolf-Team