Vulnerability · Published Jul 1, 2026 · Assigned by GitHub_M
CVE-2026-55661TinaCMS rich-text (slatejson) rendering does not sanitize link/image URLs, allowing stored XSS via dangerous URL schemes
Medium 4.8
In plain English
A medium-severity cross-site scripting in tinacms from tinacms. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Tina is a headless content management system. In versions prior to @tinacms/mdx 2.1.7 and tinacms 3.9.3, rich-text parsing and the default link/image renderers did not sanitize the url field on Slate link/image nodes. Content containing javascript: or data:text/html URLs — including case-variant, whitespace-padded, and control-character-obfuscated forms — is rendered into href/src and executes when the content is viewed. Any actor able to author rich-text content (for example a lower-privileged editor, or imported/external content) can achieve stored XSS against editors and site viewers. This issue is fixed in versions @tinacms/mdx 2.1.7 and tinacms 3.9.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @tinacms/mdx | 2.1.7 | GHSA-2vcc-5v34-9jc8 |
| npm | tinacms | 3.9.3 | GHSA-2vcc-5v34-9jc8 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| tinacms | tinacms | < 3.9.3 |
| tinacms | @tinacms/mdx | < 2.1.7 |
Weakness: CWE-79, CWE-87 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
References
- https://github.com/tinacms/tinacms/security/advisories/GHSA-2vcc-5v34-9jc8 x_refsource_CONFIRM
- https://github.com/tinacms/tinacms/pull/7056 x_refsource_MISC