CVE-2026-73427: Basecamp Trix

Low severity, CVSS 2.1. EPSS: 0.6% chance of exploitation in the next 30 days.

Trix is a what-you-see-is-what-you-get rich text editor for everyday writing. Prior to 2.1.18, Trix is vulnerable to cross-site scripting when a crafted application/x-trix-document JSON payload is dropped into an editor using the fallback Level0InputController, such as an embedded WebView without Input Events Level 2 support. The StringPiece.fromJSON method trusts href attributes from the JSON payload without sanitization, allowing a draggable element containing a javascript: URI to bypass DOMPurify sanitization and inject executable JavaScript into the DOM. Exploitation requires the victim to drag and drop attacker-controlled content, and server-side HTML sanitization can neutralize the payload on save. This issue is fixed in version 2.1.18.

Affected products

• Basecamp Trix: before 2.1.18 (fixed in 2.1.18)

Published 2026-08-12. Last modified 2026-09-09.