Grav: Single invalid UTF-8 byte disables every rule in Security::detectXss(), bypassing the page-content XSS safety gate

Vulnerability Details Component: getgrav/grav core File: system/src/Grav/Common/Security.php Function: detectXss all six entries in the $patterns array use the PCRE u modifier, invoked from Grav\Common\Data\Validation::checkSafety the save-time XSS gate for any non-security.xsswhitelist account's...

GHSA-Q2J8-X8HF-63CH Grav: Single invalid UTF-8 byte disables every rule in Security::detectXss(), bypassing the page-content XSS safety gate

Vulnerability Details Component: getgrav/grav core File: system/src/Grav/Common/Security.php Function: detectXss all six entries in the $patterns array use the PCRE u modifier, invoked from Grav\Common\Data\Validation::checkSafety the save-time XSS gate for any non-security.xsswhitelist account's...

Grav: detectXss() misses an event-handler attribute after an unpaired quote in an unquoted attribute value, giving stored XSS

Affected versions and vulnerable location - Confirmed on grav core at 78ebfc1 tag 2.0.13. - Detector: system/src/Grav/Common/Security.php:290, the onevents regex, run via patternMatches :315-330. - The onevents pattern at HEAD: "'??:\s\x00-\x20"'/|"^""|'^''on\sa-z+\s=iu - Sole save-time guard for...

EUVD-2026-60592

Grav: detectXss misses an event-handler attribute after an unpaired quote in an unquoted attribute value, giving stored XSS...

Grav: XSS Blueprint Validation Bypass via Twig String Concatenation

Summary The XSS blueprint validator Security::detectXss runs on the raw page content before Twig processing. An attacker can use Twig's string concatenation operator to dynamically construct an event handler name at render time. The validator sees "on" "error" - a harmless Twig expression - and...

CVE-2026-64851 Grav Shortcode Core Plugin: Stored XSS in shortcode-core attribute handlers

Grav Shortcode Core Plugin allows for the development shortcode plugins that utilize the common format utilized by WordPress and BBCode. Prior to 6.2.2, Grav Shortcode Core passes shortcode syntax through Security::detectXss because it contains no literal less-than character, then...

CVE-2026-64851

In Grav Shortcode Core Plugin before 6.2.2, ColorShortcode.php and related attribute handlers concatenate attacker-controlled parameters into HTML without encoding, bypassing Security::detectXss() (which misses payloads without a literal

EUVD-2026-62548

Grav Shortcode Core Plugin allows for the development shortcode plugins that utilize the common format utilized by WordPress and BBCode. Prior to 6.2.2, Grav Shortcode Core passes shortcode syntax through Security::detectXss because it contains no literal less-than character, then...

Cross-site Scripting (XSS)

Overview getgrav/grav is a Modern, Crazy Fast, Ridiculously Easy and Amazingly Powerful Flat-File CMS. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the detectXss function due to improper handling of unpaired quotes in unquoted attribute values, which allows even...

Cross-site Scripting (XSS)

Overview getgrav/grav is a Modern, Crazy Fast, Ridiculously Easy and Amazingly Powerful Flat-File CMS. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the Security::detectXss function. An attacker can inject malicious JavaScript into page content by including an...

Duplicate Advisory: Grav: detectXss() misses an event-handler attribute after an unpaired quote in an unquoted attribute value, giving stored XSS

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-vfmf-q6x9-cw96. This link is maintained to preserve external references. Original Description Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss function where unpaired quot...

Duplicate Advisory: Grav: Single invalid UTF-8 byte disables every rule in Security::detectXss(), bypassing the page-content XSS safety gate

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-q2j8-x8hf-63ch. This link is maintained to preserve external references. Original Description Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss function...

CVE-2026-75828

Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss function where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers...

CVE-2026-75834 Grav before 2.0.14 Stored XSS via Invalid UTF-8 Byte

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 pregmatch to return false for...

CVE-2026-75834

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 pregmatch to return false for...

CVE-2026-75834 Grav before 2.0.14 Stored XSS via Invalid UTF-8 Byte

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 pregmatch to return false for...

CVE-2026-75828 Grav before 2.0.15 Stored XSS via detectXss() Quote Bypass

Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss function where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers...

CVE-2026-75828

Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss function where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers...

CVE-2026-75828

Grav before 2.0.15 has a stored XSS flaw in its detectXss() sanitizer: unpaired quotes in unquoted attribute values let authenticated editors inject event handlers like onerror= that bypass validation and execute in visitor browsers. CVSS 4.0 scores this critical (9.3). Upgrade to Grav 2.0.15 to ...

CVE-2026-75828 Grav before 2.0.15 Stored XSS via detectXss() Quote Bypass

Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss function where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers...