[GHSA-cgmm-x5ww-q5cr] beautiful-mermaid contains an SVG attribute injection issue that can lead to cross-site scripting (XSS)

advisories/github-reviewed/2026/02/GHSA-cgmm-x5ww-q5cr/GHSA-cgmm-x5ww-q5cr.json

@@ -7,11 +7,11 @@
     "CVE-2026-26226"
   ],
   "summary": "beautiful-mermaid contains an SVG attribute injection issue that can lead to cross-site scripting (XSS)",
-  "details": "beautiful-mermaid versions prior to 0.1.3 contain an SVG attribute injection issue that can lead to cross-site scripting (XSS) when rendering attacker-controlled Mermaid diagrams. User-controlled values from Mermaid style and classDef directives are interpolated into SVG attribute values without proper escaping, allowing crafted input to break out of an attribute context and inject arbitrary SVG elements/attributes into the rendered output. When the generated SVG is embedded in a web page, this can result in script execution in the context of the embedding origin.",
+  "details": "beautiful-mermaid versions prior to 0.1.3 are vulnerable to Cross-Site Scripting (XSS) via SVG attribute injection. The library fails to properly escape user-supplied input in `classDef` and `style` directives within Mermaid diagrams.\n\nWhen an application uses this library to render attacker-controlled diagrams (e.g., in comments, documentation, or previews), an attacker can inject arbitrary SVG attributes (such as `onload` or `onerror` events). This results in the execution of malicious JavaScript in the context of the victim's session, potentially leading to Account Takeover (ATO) via session cookie theft or unauthorized actions.",
   "severity": [
     {
       "type": "CVSS_V4",
-      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
+      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:H/SI:H/SA:N"
     }
   ],
   "affected": [
@@ -67,6 +67,7 @@
   ],
   "database_specific": {
     "cwe_ids": [
+      "CWE-116",
       "CWE-79"
     ],
     "severity": "MODERATE",