CVE-2026-66921

Pivotick’s Markdown node-reference renderer failed to HTML-escape the attacker-controlled nodeName value before interpolating it into both the data-node-name attribute and the body of a generated <span> element. Because the node-reference tokenizer rejected only square brackets, a crafted node name could still contain quotation marks, angle brackets, or other HTML metacharacters. An attacker could therefore terminate the quoted attribute or inject additional HTML elements and event-handler attributes. When malicious node-reference content is rendered by a consumer that does not apply DOMPurify or equivalent sanitization, arbitrary JavaScript may execute in the victim’s browser in the security context of the application. Successful exploitation requires a victim to open or render a crafted graph or note and could allow the attacker to access same-origin information, modify displayed content, or perform actions using the victim’s session. The patch resolves the issue by applying context-appropriate HTML escaping to node names before inserting them into either HTML text or quoted attribute values. The shared escaping function now encodes ampersands, angle brackets, and both types of q