A CMS user without the ability to edit a page could access revisions of the page through the revision compare view if they knew the primary key of two revisions. This could potentially result in disclosure of sensitive information.
Patches
Patched versions have been released as Wagtail 7.0.7 and 7.3.2. The new 7.4 LTS feature release also incorporates this fix.
Workarounds
No workaround is available.
Acknowledgements
Many thanks to Seoyoung Kang @seoyoung-kang from AhnLab and an independent security researcher for reporting this issue.
For more information
If there are any questions or comments about this advisory: