Kestra vulnerable to stored XSS via custom Markdown [[link]] attribute injection

Summary Kestra’s Markdown renderer supports a custom link ... syntax that is converted into a custom HTML element. The custom Markdown parser allows attacker-controlled attributes to be rendered into the generated element without proper allowlisting or sanitization. As a result, a user who can...

CVE-2026-55839 Kestra: Stored XSS via custom Markdown [[link]] attribute injection

Kestra is an open-source, event-driven orchestration platform. Prior to 1.3.24, Kestra's custom Markdown parser in ui/src/utils/markdownplugins/link.ts allows a user with permission to create or update a Flow description to inject JavaScript event-handler attributes through the custom link syntax...