TinyMCE Cross-Site Scripting (XSS) vulnerability using through data-mce- prefixed src, href, style attributes

### Impact Stored XSS vulnerability via unsanitized data-mce-* attributes (data-mce-href, data-mce-src, data-mce-style). Allows attackers to inject malicious values that override safe attributes during serialization, bypassing validation. ### Patches Patched by stripping unsafe data-mce-* attributes during parsing. Users should upgrade to the latest patched versions (5 LTS, 7.x, 8.x). ### Workarounds No official workaround available. ### Fix To avoid this vulnerability: Upgrade to TinyMCE 8.5.1 or higher. Upgrade to TinyMCE 7.9.3 or higher. Upgrade to TinyMCE 5.11.1 LTS or higher for TinyMCE 5.x (only available as part of commercial [long-term support](https://www.tiny.cloud/long-term-support/) contract). ### Acknowledgements Tiny thanks [Tadi Kadango](https://github.com/mtrill47) ([website](https://tadiwakadango.com/)) and [Ivan Babenko](https://github.com/he1d3n) for their help identifying this vulnerability.

Source published

5 Jun 2026 20:27:50 UTC

Source modified

10 Sep 2026 03:51:10 UTC

Observed here

23 Oct 2026 16:01:25 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Publisher rating · HIGH