Vulnerability Description
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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/getgrav/grav/security/advisories/GHSA-2c4f-86xc-cr74
- https://www.vulncheck.com/advisories/grav-before-xss-via-twig-string-concatenati
- https://github.com/getgrav/grav/security/advisories/GHSA-2c4f-86xc-cr74
FAQ
What is CVE-2026-61453?
CVE-2026-61453 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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 proce...
How severe is CVE-2026-61453?
CVE-2026-61453 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-61453?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.