CVE-2026-126774
@tinacms/mdx before 2.4.2 Code Injection via MDX Serializer Rich-Text Values
@tinacms/mdx before 2.4.2 contains a code injection vulnerability in its MDX serializer, which writes rich-text values into MDX expressions without escaping them. Authenticated content editors can save crafted values that break out of list field or highlightColor expressions in the stored .mdx file, executing JavaScript in visitors' browsers or on build and server-side rendering hosts.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| @tinacms/mdx tinacms %40tinacms/mdx
npm |
≥ 0; < 2.4.2 (affected, semver) 2.4.2 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 8.8 high |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N | CNA: VulnCheck |
| 3.1 / 8.2 high |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N | CNA: VulnCheck |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/tinacms/tinacms/security/advisories/GHSA-6vw5-w22x-ghxvCNA: VulnCheck · vendor-advisory
- https://github.com/tinacms/tinacms/pull/7958CNA: VulnCheck · patch, issue-tracking
- https://github.com/tinacms/tinacms/commit/19285c6deeee52c380e8b2fdeafedc9530dc0618CNA: VulnCheck · patch
- https://github.com/tinacms/tinacms/releases/tag/%40tinacms/mdx%402.4.2CNA: VulnCheck · release-notes
- https://github.com/tinacms/tinacms/blob/%40tinacms/mdx%400.60.3/packages/%40tinacms/mdx/src/stringify/acorn.ts#L81CNA: VulnCheck · technical-description
- https://www.vulncheck.com/advisories/tinacms-mdx-before-2.4.2-code-injection-via-mdx-serializer-rich-text-valuesCNA: VulnCheck · third-party-advisory
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