Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
From VID-0A50BB48-625F-11EC-A1FB-080027CB2F6F:
Mediawiki reports:
(T292763. CVE-2021-44854) REST API incorrectly publicly caches
autocomplete search results from private wikis.
(T271037, CVE-2021-44856) Title blocked in AbuseFilter can be created via
Special:ChangeContentModel.
(T297322, CVE-2021-44857) Unauthorized users can use action=mcrundo to
replace the content of arbitrary pages.
(T297322, CVE-2021-44858) Unauthorized users can view contents of private
wikis using various actions.
(T297574, CVE-2021-45038) Unauthorized users can access private wiki
contents using rollback action
(T293589, CVE-2021-44855) Blind Stored XSS in VisualEditor media dialog.
(T294686) Special:Nuke doesn't actually delete pages.
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