Trix: XSS via JSON deserialization bypass in drag-and-drop (Level0InputController)
Published Aug 12, 2026
2.1
LOWCVSS 4.0
EPSS 0.57%
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 products
-
- Version < 2.1.18StatusaffectedConstraints-
- Version
No data.
No data.
No Red Hat product state for this CVE.
trix
npm
Introduced 0 Fixed 2.1.18action_text-trix
RubyGems
Introduced 0 Fixed 2.1.18
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| npm | trix | 0 | 2.1.18 |
| RubyGems | action_text-trix | 0 | 2.1.18 |
Remediation
Red Hat statement
The version of action_text-trix shipped in Red Hat products is not affected by this vulnerability as it already includes the fix.
Red Hat mitigation
Upgrading to Trix 2.1.18+ resolves this issue. Applications using server-side HTML sanitization (such as Rails' built-in sanitizer) provide additional protection.
Metrics
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
1 other source (NVD) ▾
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Aug 13, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Aug–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.57% (0.00575) | 45.41th | v5 (v2026.06.15) |
| Aug 13, 2026 | 0.33% (0.00326) | 25.31th | v5 (v2026.06.15) |
References (10)
- https://access.redhat.com/security/cve/CVE-2026-73427 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2514987 Issue Tracking
- https://github.com/advisories/GHSA-53p3-c7vp-4mcc Advisory
- https://github.com/basecamp/trix/commit/9c0a993d9fc2ffe9d56b013b030bc238f9c0557c x_refsource_MISC
- https://github.com/basecamp/trix/pull/1293 x_refsource_MISC
- https://github.com/basecamp/trix/releases/tag/v2.1.18 x_refsource_MISC
- https://github.com/basecamp/trix/security/advisories/GHSA-53p3-c7vp-4mcc x_refsource_CONFIRM
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/action_text-trix/GHSA-53p3-c7vp-4mcc.yml
- https://nvd.nist.gov/vuln/detail/CVE-2026-73427
- https://www.cve.org/CVERecord?id=CVE-2026-73427
Change history (0)
No recorded changes yet.