Nextcloud Server is a self hosted personal cloud system. MD5 hashes were used to check background jobs for their uniqueness. This increased the chances of a background job with arguments falsely being identified as already existing and not be queued for execution. By changing the Hash to SHA256 the probability was heavily decreased. It is recommended that the Nextcloud Server is upgraded to 28.0.10, 29.0.7 or 30.0.0.

Nextcloud Server is a self hosted personal cloud system. Due to a pre-flighted HEAD request, the link reference provider could be tricked into downloading bigger websites than intended, to find open-graph data. It is recommended that the Nextcloud Server is upgraded to 28.0.10 or 29.0.7 and Nextcloud Enterprise Server is upgraded to 27.1.11.8, 28.0.10 or 29.0.7.

Nextcloud Server is a self hosted personal cloud system. The OAuth2 client secrets were stored in a recoverable way, so that an attacker that got access to a backup of the database and the Nextcloud config file, would be able to decrypt them. It is recommended that the Nextcloud Server is upgraded to 28.0.10 or 29.0.7 and Nextcloud Enterprise Server is upgraded to 27.1.11.8, 28.0.10 or 29.0.7.

Nextcloud Server is a self hosted personal cloud system. After an attacker got access to the session of a user or administrator, the attacker would be able to create, change or delete external storages without having to confirm the password. It is recommended that the Nextcloud Server is upgraded to 28.0.12, 29.0.9 or 30.0.2.

Nextcloud Server is a self hosted personal cloud system. After storing "Global credentials" on the server, the API returns them and adds them into the frontend again, allowing to read them in plain text when an attacker already has access to an active session of a user. It is recommended that the Nextcloud Server is upgraded to 28.0.11, 29.0.8 or 30.0.1 and Nextcloud Enterprise Server is upgraded to 25.0.13.13, 26.0.13.9, 27.1.11.9, 28.0.11, 29.0.8 or 30.0.1.

Nextcloud Server is a self hosted personal cloud system. When a server is configured to only allow sharing with users that are in ones own groups, after a user was removed from a group, previously shared items were not unshared. It is recommended that the Nextcloud Server is upgraded to 22.2.11 or 23.0.11 or 24.0.6 and Nextcloud Enterprise Server is upgraded to 22.2.11 or 23.0.11 or 24.0.6.

Nextcloud Server is a self hosted personal cloud system. After an admin enables the default-disabled SVG preview provider, a malicious user could upload a manipulated SVG file referencing paths. If the file would exist the preview of the SVG would preview the other file instead. It is recommended that the Nextcloud Server is upgraded to 27.1.10, 28.0.6 or 29.0.1 and Nextcloud Enterprise Server is upgraded to 24.0.12.15, 25.0.13.10, 26.0.13.4, 27.1.10, 28.0.6 or 29.0.1.

In Nextcloud Desktop Client 3.13.1 through 3.13.3 on Linux, synchronized files (between the server and client) may become world writable or world readable. This is fixed in 3.13.4.

Nextcloud Server is a self hosted personal cloud system. Private shared calendar events' recurrence exceptions can be read by sharees. It is recommended that the Nextcloud Server is upgraded to 27.1.10 or 28.0.6 or 29.0.1 and that the Nextcloud Enterprise Server is upgraded to 27.1.10 or 28.0.6 or 29.0.1.

user_oidc app is an OpenID Connect user backend for Nextcloud. An attacker could potentially trick the app into accepting a request that is not signed by the correct server. It is recommended that the Nextcloud user_oidc app is upgraded to 1.3.5, 2.0.0, 3.0.0, 4.0.0 or 5.0.0.