CVE-2026-73428: Trix: Stored XSS via HTMLParser attribute injection on paste
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 stored cross-site scripting when crafted HTML is pasted into the editor. HTMLParser processes a mock attachment in a `<span>` with an empty `data-trix-attachment="{}"` value, causing data-trix-attributes to be applied to a plain string piece. StringPiece.fromJSON accepts an unvalidated href, allowing a javascript: URI to enter the document model and serialized HTML and execute when another user renders and clicks the content. Applications that apply server-side HTML sanitization can neutralize the payload on save. This issue is fixed in version 2.1.18.
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N · CWE-79
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
basecamp: trix
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/basecamp/trix/commit/9c0a993d9fc2ffe9d56b013b030bc238f9c0557c (opens in new tab)
- github.com/basecamp/trix/pull/1293 (opens in new tab)
- github.com/basecamp/trix/releases/tag/v2.1.18 (opens in new tab)
- github.com/basecamp/trix/security/advisories/GHSA-53g2-mvcc-q9x3 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)