CVE-2026-73158: medium-severity vulnerability in MISP cti-transmute

Affected versions of cti-transmute insufficiently validate saved graph configuration data. Graph configurations can contain style properties that are later consumed by Pivotick, and Pivotick interprets svgIcon as HTML. Because saved configurations may be created by one user and later displayed to other users—including administrators—a malicious user could store a crafted svgIcon value that executes script in another viewer’s browser. The fix introduces a strict configuration schema on both the server and client. Only known properties are accepted, style entries are limited to shape, color, and size, and dangerous properties such as svgIcon and iconClass are explicitly rejected. Existing stored configurations are also sanitized when listed and again before being applied in the browser.