GHSA-x5cx-w6p2-mxf2

### Impact A CMS user with "add" permission over a snippet model, but not "change" or "view" permission, could copy an existing snippet that they do not have access to, allowing them to view its contents. ### Patches Patched versions have been released as Wagtail 7.0.9, 7.3.4, 7.4.3 and 8.0rc2. ### Workarounds N/A ### Acknowledgements Many thanks to tinyb0y for reporting this issue. ### For more information If you have any questions or comments about this advisory: * Visit Wagtail's [support channels](https://docs.wagtail.org/en/stable/support.html) * Email us at [[email protected]](mailto:[email protected]) (view our [security policy](https://github.com/wagtail/wagtail/security/policy) for more information).