Nextcloud server is an open source home cloud platform. Affected versions of Nextcloud stored OAuth2 tokens in plaintext which allows an attacker who has gained access to the server to potentially elevate their privilege. This issue has been addressed and users are recommended to upgrade their Nextcloud Server to version 25.0.8, 26.0.3 or 27.0.1. There are no known workarounds for this vulnerability.

Nextcloud is an open source home cloud server. When Memcached is used as `memcache.distributed` the rate limiting in Nextcloud Server could be reset unexpectedly resetting the rate count earlier than intended. Users are advised to upgrade to versions 25.0.11, 26.0.6 or 27.1.0. Users unable to upgrade should change their config setting `memcache.distributed` to `\OC\Memcache\Redis` and install Redis instead of Memcached.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 20.0.0 and prior to versions 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1, a missing password confirmation allowed an attacker, after successfully stealing a session from a logged in user, to create app passwords for the victim. Nextcloud server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 19.0.0 and prior to versions 19.0.13.10, 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1, a malicious user could delete any personal or global external storage, making them inaccessible for everyone else as well. Nextcloud server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 19.0.13.10, 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. As a workaround, disable app files_external. This also makes the external storage inaccessible but retains the configurations until a patched version has been deployed.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 24.0.4 and prior to versions 25.0.9, 26.0.4, and 27.0.1, when a folder with images or an image was shared without download permissions, the user could add the image inline into a text file and download it. Nextcloud Server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.9, 26.0.4, and 27.0.1, unauthenticated users could send a DAV request which reveals whether a calendar or an address book with the given identifier exists for the victim. Nextcloud Server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 22.0.0 and prior to versions 22.2.10.13, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1, missing protection allows an attacker to brute force the client secrets of configured OAuth2 clients. Nextcloud Server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 22.2.10.13, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 22.0.0 and prior to versions 22.2.10.13, 23.0.12.8, 24.0.12.4, 25.0.8, 26.0.3, and 27.0.1, a user can access files inside a subfolder of a groupfolder accessible to them, even if advanced permissions would block access to the subfolder. Nextcloud Server versions 25.0.8, 26.0.3, and 27.0.1 and Nextcloud Enterprise Server versions 22.2.10.13, 23.0.12.8, 24.0.12.4, 25.0.8, 26.0.3, and 27.0.1 contain a patch for this issue. No known workarounds are available.