getgrav/grav · Duplicate Advisory: Grav: Single invalid UTF-8 byte disables every rule in Security::detectXss(), bypassing the page-content XSS safety gate
Affects getgrav/gravSource GCVE Database
CVSS 5.4 Medium.
Data as of 18 Sep 2026, 01:26 UTC
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NWhat to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Packagistgetgrav/grav | Affected– | Fixed in– |
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AI-suggested
Since the advisory is a duplicate and withdrawn, consult the original advisory GHSA-q2j8-x8hf-63ch for official patch or mitigation details. Until patched, restrict page-edit permissions to trusted users and monitor for suspicious content.
Description
Grav versions before 2.0.14 have a stored cross-site scripting (XSS) vulnerability in the Security::detectXss() function. A single invalid UTF-8 byte in page content causes all XSS detection patterns to fail, bypassing the XSS safety check. An authenticated user with page-edit permissions but without the XSS whitelist privilege can exploit this to store malicious JavaScript that executes in visitors' browsers.