Vulnerability · Published Aug 12, 2026 · Assigned by GitHub_M
CVE-2026-73427Trix: XSS via JSON deserialization bypass in drag-and-drop (Level0InputController)
Low 2.1
In plain English
A low-severity cross-site scripting in trix from basecamp. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| RubyGems | action_text-trix | 2.1.18 | GHSA-53p3-c7vp-4mcc |
| npm | trix | 2.1.18 | GHSA-53p3-c7vp-4mcc |
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/basecamp/trix/security/advisories/GHSA-53p3-c7vp-4mcc x_refsource_CONFIRM
- https://github.com/basecamp/trix/pull/1293 x_refsource_MISC
- https://github.com/basecamp/trix/commit/9c0a993d9fc2ffe9d56b013b030bc238f9c0557c x_refsource_MISC
- https://github.com/basecamp/trix/releases/tag/v2.1.18 x_refsource_MISC