Authenticated Non-Members Can Enumerate Team Resources via API in Nextcloud Server

When a team was configured as "visible to everyone", the web UI correctly blocked non-members from viewing the team ("You are not a member of ..."), but the resources API endpoint could still be called directly, allowing any authenticated non-member to enumerate the team's internal resources and their identifiers. This does not grant access to the contents of the discovered resources themselves, only their existence, names, and identifiers.

Files with # in name not flagged as confidential in Nextcloud

A user could create a docx or odt file with a # in the filename with confidential information such as a credit card number and have it not be marked as confidential.

Public Link Allows Unauthorized Page Creation in Nextcloud Collectives

A public shared collective always allowed recipients of the link to create pages.

nextcloud: Nextcloud: Denial of Service via federated share endpoint abuse

Abusing the federated share endpoint, an attacker can write arbitrary rows into the oc_share_external database table. These rows persist indefinitely — there is no automatic cleanup mechanism. Three distinct denial-of-service conditions follow from this write primitive, all triggered from the same unauthenticated source and all self-renewing on a 24-hour cycle for as long as the injected rows remain in the database.

Missing Token Type Check Exposes WOPI Configuration in Nextcloud Richdocuments

A missing token type check allowed to retrieve more additional information about the WOPI configuration with a user or guest token.

SSR Leakage of JWT Tokens in Nextcloud Whiteboard via DevTools Protocol

A SSRF vulnerability found that enables access to internal Chrome Devtools Protocol APIs that can leak the JWT authentication token for another user. A low privileged attacker could continually exploit this vulnerability to leak the JWT authentication token for another user when they start a recording, which then enables the attacker read/write access to the victim's Whiteboard.

Group-level link‑sharing bypass in Nextcloud Tables

The user in a group can bypass the group restriction set by an administrator on link sharing, creating share links for a table even though they shouldn't have that permission.

tables: Nextcloud Tables: Information disclosure via missing permission check on share-listing endpoint

The Tables app's share-listing endpoint (GET /apps/tables/share/table/{tableId}) did not verify that the requesting user has manage-level permission on the table before returning the full list of share recipients (users, groups, and teams) along with their permission levels. A user who was only granted read-data access to a table, and who is correctly prevented from seeing this information in the web UI, could call the endpoint directly to enumerate everyone the table is shared with and their access levels. This does not expose the table's data itself beyond what the read-data grant already permits, only the list of share recipients and their permission levels.

App Passwords Bypass Password Confirmation on Sensitive Endpoints

App passwords were allowed to bypass password confirmation on sensitive endpoints.

Nextcloud Android Client Forces Logout for Profile Takeover

An issue in Nextcloud versionCode 30390190 allows attackers to force victim users to logout of their accounts and switch to an attacker controlled progile, bypassing authentication.

Inadequate Input Validation in Emoji Update Endpoint Causes Layout Breakage

The emoji field in the page emoji update endpoint does not properly validate user input. By injecting long text and line breaks, the sidebar layout becomes broken and can hide other items.

Permanent File Locks due to Improper Access Control in Nextcloud Server

File owners were unable to unlock TYPE_TOKEN locks placed by other users, leaving files permanently locked with no recovery path outside of the database.

After guessing a 62^15 complex unique identifier, a malicious logged in user was able to retrieve a list of memberships for a circle they are not a member of.

A vulnerability in the team folders (formerly group folders) app when used in combination with the workspace app allowed API/REST-only delegated administrators to bypass folder-level authorization controls. The workspace app enables organizations to delegate limited administrative privileges for team folder management via API/REST only, restricting access to folders for which the admin has advanced permissions.

The Approval app's approve/reject endpoint is meant to require the file's current etag as a freshness check, preventing an approver from approving or rejecting a file whose contents changed after they reviewed it. The backend only enforced this check when the etag parameter was present and non-empty in the request. An attacker able to intercept and modify the approval request could omit the etag field entirely, bypassing the freshness check and approving or rejecting a file version they never reviewed.

The Deck config API allows authenticated users to set board-scoped configuration keys for arbitrary board IDs without validating whether the user owns or has permission to manage the referenced board.

Circles' remote-instance signature verification fetches the attacker-supplied keyId URL before trust in the remote instance is established, and explicitly allows local/private addresses for this request, bypassing Nextcloud's core SSRF protections. The public, unauthenticated endpoints POST /apps/circles/event/ and POST /apps/circles/incoming/ reach this code path, allowing any unauthenticated user to force the server to issue a GET request to an internal address. The response body of the internal request is never returned to the requester, so this is blind SSRF: an attacker can determine whether an internal service is reachable, but cannot read its response contents through this endpoint alone.

The Photos app's filter-based "smart albums" build their file listing using the search configuration (photosSourceFolders) of the user viewing the album, rather than the album owner's configuration. When an album owner shares a smart album with another user, that user's own folder configuration is used to determine which of the owner's files are searched — allowing them to discover files (name, file ID, and other metadata) in folders the album owner never intended to include in the shared album. This requires the album owner to have shared a filter-based smart album with the attacker; it does not allow access to arbitrary users' files without such a share.

Arbitrary Cross‑User File Locking via WebDAV Paths

Any authenticated user can lock or unlock files they do not own by targeting absolute WebDAV paths of other users. The DAV plugin resolves files from the absolute request URI without verifying that the path segment matches the authenticated session user. This enables: Cross-user manual locks : attacker locks a victim's files, blocking writes (PUT/MOVE/DELETE, editor saves). Lock-token disclosure: the app returns the lock token to unauthorized callers, enabling them to remove token-based locks (client locks) of other users.

Windmill < 1.603.3 File Ownership Handling SQLi RCE

Windmill CE and EE versions 1.276.0 through 1.603.2 contain an SQL injection vulnerability in the folder ownership management functionality that allows authenticated attackers to inject SQL through the owner parameter. An attacker can use the injection to read sensitive data such as the JWT signing secret and administrative user identifiers, forge an administrative token, and then execute arbitrary code via the workflow execution endpoints.