@tinacms/web-components: `tina-markdown` writes rich-text link URLs into `href` without scheme validation, allowing stored XSS — GHSA-C42Q-QVC3-J6VG

Summary

### Summary `<tina-markdown>` renders a rich-text AST into the DOM and, for `a` nodes, assigns the node's URL straight to the anchor's `href` with no scheme check. A link authored in the CMS as `javascript:…` renders as a live `javascript:` anchor, so a visitor who clicks it executes attacker-supplied script in the site's origin. Every sibling renderer in the repository already sanitizes these URLs; this one does…

Timeline

Published by source

2026-10-09

Risk context

• Reported severity or threat level: high.
• Reported CVSS score: 7.6 out of 10.
• Review exposure for the affected product or family: npm: @tinacms/web-components.

Product

npm: @tinacms/web-components

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-C42Q-QVC3-J6VG

Source

GitHub

Vendor

GitHub

Published by source

2026-10-09

Last source activity

2026-10-09

Additional identifiers

CVE-2026-108260

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.