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

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Tina is a headless content management system. Prior to 0.2.1, the tina-markdown element in packages/@tinacms/web-components/src/tina-markdown.js assigns a rich-text node.url value directly to an anchor href without validating the URL scheme. A content author can store a link using a script-capable scheme, and a visitor who clicks the rendered link executes attacker-controlled script in the site's origin. The script can access same-origin application data and, when the visitor is an editor or administrator, may expose credentials stored by the TinaCMS admin on that origin. This issue is fixed in version 0.2.1.

[ Fixes ]Fixes and patches

• @tinacms/web-components 0.2.1Fixed version · GitHub Advisories · npm package @tinacms/web-components: upgrade to 0.2.1 or later (affected <= 0.2.0)

[ Packages ]Affected open-source packages

• @tinacms/web-components npmAffected <= 0.2.0 · fixed in 0.2.1 · GHSA-c42q-qvc3-j6vg

[ References ]References

• github.com/tinacms/tinacms/commit/5295e077f0d279c35686a0e481a15e33a4877e3b
• github.com/tinacms/tinacms/pull/7523
• github.com/tinacms/tinacms/releases/tag/@tinacms/web-components@0.2.1
• github.com/tinacms/tinacms/security/advisories/GHSA-c42q-qvc3-j6vg