{"id":"GHSA-373m-p57p-8665","title":"Duplicate Advisory: Grav: XSS Blueprint Validation Bypass via Twig String Concatenation","summary":"Duplicate Advisory: Grav: XSS Blueprint Validation Bypass via Twig String Concatenation","severity":"medium","cvss":6.1,"cwe":["CWE-79"],"vendor":"getgrav","product":"getgrav/grav","ecosystem":"composer","affected":["getgrav/grav = 2.0.0"],"published":"2026-07-15","updated":"2026-09-16","sourceUpdated":"2026-09-16T22:13:09Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-373m-p57p-8665","references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-2c4f-86xc-cr74"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61453"},{"url":"https://www.vulncheck.com/advisories/grav-before-xss-via-twig-string-concatenation"},{"url":"https://github.com/advisories/GHSA-373m-p57p-8665"}],"tags":["ghsa","composer"],"ingestedAt":"2026-09-16T23:07:58.095Z","slug":"GHSA-373m-p57p-8665","body":"## Overview\n\n### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-2c4f-86xc-cr74. This link is maintained to preserve external references.\n\n### Original Description\nGrav 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.\n\n## Affected packages\n\n- `getgrav/grav = 2.0.0`\n\n## Remediation\n\nRefer to the advisory for the patched release.","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}