Trix is vulnerable to XSS through JSON deserialization bypass in drag-and-drop (Level0InputController)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

2.1 · 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 · score source

EPSS

• CVE-2026-73427: 0.57% estimated exploitation activity in the next 30 days; percentile 47.48 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact The Trix editor, in versions prior to 2.1.18, is vulnerable to XSS when a crafted application/x-trix-document JSON payload is dropped into the editor in environments using the fallback Level0InputController (e.g., embedded WebViews lacking Input Events Level 2 support). The StringPiece.fromJSON method trusted href attributes from the JSON payload without sanitization. An attacker could craft a draggable element containing a javascript: URI in the href attribute that, when dropped into a vulnerable editor, would bypass DOMPurify sanitization and inject executable JavaScript into the DOM. Exploitation requires a specific environment (Level0InputController fallback) and social engineering (victim must drag and drop attacker-controlled content into the editor). Applications using server-side HTML sanitization (such as Rails' built-in sanitizer) are additionally protected, as the payload is neutralized on save. Patches Update Recommendation: Users should upgrade to Trix editor…

Published by the source

29 Mar 2026, 15:22 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-53p3-c7vp-4mcc

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-53p3-c7vp-4mcc

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# Patch Next advisory brief: CVE-2026-73427

Advisory: Trix is vulnerable to XSS through JSON deserialization bypass in drag-and-drop (Level0InputController)
IDs: CVE-2026-73427, GHSA-53p3-c7vp-4mcc
Record: https://patchnext.com/advisories/cve-2026-73427 (revision 3, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: action_text-trix 2.1.18; trix 2.1.18. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems action_text-trix: affected < 2.1.18; fixed in 2.1.18
- npm trix: affected < 2.1.18; fixed in 2.1.18

## Suggested inspection (read-only)
- RubyGems action_text-trix: check the installed version with your package manager.
- `npm ls trix --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on action_text-trix, trix.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-53p3-c7vp-4mcc (OSV record GHSA-53p3-c7vp-4mcc lists affected ranges: npm trix >=0 =0 <2.1.18 (fixed))
- Verified: https://github.com/advisories/GHSA-53p3-c7vp-4mcc (GitHub-reviewed advisory GHSA-53p3-c7vp-4mcc lists affected ranges: npm trix >=0 =0 <2.1.18)

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