CVE-2026-73428

Trix: Stored XSS via HTMLParser attribute injection on paste

MEDIUM
4.6
CVSS Score
Published: August 13, 2026 at 10:04 PM UTC
Updated: September 18, 2026 at 08:19 PM UTC
1 product affected across 1 vendorTrix

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Severity
MEDIUM4.6
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.1.18
Affected range stops below 2.1.18, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.6MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79

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