Embedded font-family names (word/fontTable.xml) were interpolated unescaped into an injected @font-face <style> and into the print window's document.write(). A crafted name injects page-wide CSS on open, and breaks out of <style> into executable HTML on Print.

Opening a crafted .docx applies attacker-controlled CSS page-wide with zero clicks (overlay/phishing, attribute-selector exfiltration of input values, tracking beacons). Clicking Print escalates to script execution in the embedder's origin.

Upgrade to 1.8.3. Font names are CSS-escaped before interpolation (quotes, backslash, < >, and CSS newlines), and the print window is assembled with DOM APIs instead of document.write.