XWiki is an open-source wiki software platform. Versions 16.10.10 and below, 17.0.0-rc-1 through 17.4.3 and 17.5.0-rc-1 through 17.6.0 contain a REST API which doesn't enforce any limits for the number of items that can be requested in a single request at the moment. Depending on the number of pages in the wiki and the memory configuration, this can lead to slowness and unavailability of the wiki. As an example, the /rest/wikis/xwiki/spaces resource returns all spaces on the wiki by default, which are basically all pages. This issue is fixed in versions 17.4.4 and 16.10.11.