Tandoor Recipes permitted authenticated users to insert arbitrary <style> tags into recipe step instructions. The server-side sanitizer whitelisted the <style> element, so the CSS was stored and subsequently served through the API without further cleansing. When a client reads the instructions_markdown field and renders it as HTML, the injected CSS is executed in the user’s browser, allowing the attacker to manipulate the page layout, overlay phishing interfaces, deface content, or perform CSS-based data exfiltration. The flaw is a classic stored injection and is catalogued as CWE‑79.

The vulnerability exists in all versions of TandoorRecipes:recipes released before 2.6.4. Users running any pre‑2.6.4 build are affected; upgrade to version 2.6.4 or later resolves the issue.

The CVSS base score of 5.4 indicates moderate severity, and the EPSS score of less than 1% suggests low likelihood of current exploitation. The issue is not listed in the CISA KEV catalog, but the attack requires an authenticated session and a client that renders the API‑supplied markdown as HTML. If these conditions are met, the risk of UI defacement and data leakage exists.