Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) in Trix - #VU128363
Published: April 28, 2026
Vulnerability identifier: #VU128363
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-80
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Basecamp
Affected software:
Trix
Trix
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary JavaScript code in the user's session.
The vulnerability exists due to cross-site scripting in the data-trix-attachment attribute when rendering attachment payloads as HTML and the content is clicked. A remote user can inject malicious code into a crafted attachment attribute to execute arbitrary JavaScript code in the user's session.
User interaction is required to click the rendered content.
Remediation
Install security update from vendor's website.