getgrav Grav up to 2.0.0 Twig detectXss content cross site scripting

Summaryinfo

A vulnerability has been found in getgrav Grav up to 2.0.0 and classified as problematic. This affects the function detectXss of the component Twig Handler. This manipulation of the argument content causes cross site scripting. The identification of this vulnerability is CVE-2026-61453. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in getgrav Grav up to 2.0.0. It has been declared as problematic. Affected by this vulnerability is the function detectXss of the component Twig Handler. The manipulation of the argument content with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

Grav v2.0.0 contains a cross-site scripting vulnerability (fixed in 2.0.1). The XSS blueprint validator (Security::detectXss()) runs on raw page content before Twig processing. When Twig content processing is enabled (twig_content.process_enabled: true), an attacker with page-write API permission can use Twig's string concatenation operator (~) to dynamically construct event handler names, dangerous tag names, or dangerous protocols at render time (e.g. {% set x = "on" ~ "error" %}). The validator sees only the harmless Twig expression and allows the content, but after Twig rendering the output (rendered via {{ page.content|raw }}) contains an active payload such as <img src=1 onerror=alert(1)>, executing arbitrary JavaScript in visitors' browsers.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-61453 since 07/09/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 2.0.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-44650). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• getgrav

Name

• Grav

Version

• 2.0

Website

• Product: https://github.com/getgrav/grav/

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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