Nextcloud vulnerabilities

CVE-2026-45275 Medium · 6.5 CWE-285 Jun 1, 2026

Nextcloud: Authorization bypass in approval feature allows unauthorized file sharing with approvers

Nextcloud is an open source content collaboration platform. Prior to version 2.7.2, a privilege escalation vulnerability exists in the Approval app that allows a user without sharing permissions to force the system to share a file with approvers. This results in an authorization bypass and privilege escalation, allowing unauthorized distribution of restricted files. This issue has been patched in version 2.7.2.

CVE-2026-45267 Medium · 6.5 CWE-200 Jun 1, 2026

Nextcloud: Missing permission check for from submissions

Nextcloud is an open source content collaboration platform. Prior to version 5.2.6, a missing permissions check allowed users to request reading form submissions of other users. This issue has been patched in version 5.2.6.

CVE-2026-45266 Low · 3.5 CWE-284 Jun 1, 2026

Nextcloud: Unauthorized force-mute from missing permission check when using internal signaling

Nextcloud is an open source content collaboration platform. Prior to versions 21.1.10, 22.0.11, and 23.0.3, a low-privileged user can force other user's microphones to be muted in calls when no High-performance Backend is installed. This issue has been patched in versions 21.1.10, 22.0.11, and 23.0.3.

CVE-2026-45264 Medium · 4.3 CWE-284 Jun 1, 2026

Nextcloud: ACL Rename Permission Bypass in Team Folders Allows Unauthorized File Renames

Nextcloud is an open source content collaboration platform. From versions 17.0.0 to before 17.0.15, 18.0.0 to before 18.1.12, 19.0.0 to before 19.1.16, 20.0.0 to before 20.1.11, and 21.0.0 to before 21.0.4, a user with READ and CREATE permission, but no UPDATE permission for a team folder can rename files in the team folder. This issue has been patched in versions 17.0.15, 18.1.12, 19.1.16, 20.1.11, and 21.0.4.

CVE-2026-45159 Low · 3.5 CWE-639 Jun 1, 2026

Nextcloud: Files drop share links for end-to-end encrypted folders allowed to drop files into other folders of the share owner

Nextcloud is an open source content collaboration platform. From versions 1.15.0 to before 1.15.4, 1.16.0 to before 1.16.3, 1.17.0 to before 1.17.1, and 1.18.0 to before 1.18.1, a malicious user with access to an end-to-end encrypted files drop link was able to also drop files into other end-to-end encrypted folders of the share owner. Reading and modifying of other files was not possible. This issue has been patched in versions 1.15.4, 1.16.3, 1.17.1, 1.18.1, and 2.0.0-rc.7.

CVE-2026-45157 Medium · 6.3 CWE-284 Jun 1, 2026

Nextcloud: Valid share tokens allow to access tempory upload files of share owner

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, when a malicious user has access to a file share of a user, they could use this share token to also access the chunking upload directly and see temporary part files during on going uploads. It is recommended that the Nextcloud Server is upgraded to 32.0.9 or 33.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 26.0.13.26, 27.1.11.25, 28.0.14.17, 29.0.16.16, 30.0.17.9, 31.0.14.5, 32.0.9 or 33.0.3

CVE-2026-45156 High · 8.1 CWE-287 Jun 1, 2026

Nextcloud: Authentication Bypass in ID4me handling via Missing JWT Signature Verification in User OIDC

Nextcloud is an open source content collaboration platform. From versions 0.3.0 to before 3.1.0, 5.0.0 to before 5.1.0, and 6.0.0 to before 6.4.0, a missing signature verification in User OIDC allowed a malicious ID4me authority to identify as any user. This issue has been patched in versions 3.1.0, 4.1.0, 5.1.0, 6.4.0 and 8.3.0.

CVE-2026-45155 Low · 2.6 CWE-639 Jun 1, 2026

Nextcloud: Private circle can be added to another circle via API

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.7 and 33.0.0 to before 33.0.1, a missing access check on API level allowed to add unknown circles by their ID directly to other circles. Since circle IDs have 62^15 complexity by default this is still unlikely to be executable at will, but if access to an ID was available via another source, memberships could be tracked like this. It is recommended that the Nextcloud Server is upgraded to 32.0.7 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 29.0.16.14, 30.0.17.8, 31.0.14.3, 32.0.7 or 33.0.1

CVE-2026-45154 Low · 2.6 CWE-284 Jun 1, 2026

Nextcloud: Improper Access Control in Collectives

Nextcloud is an open source content collaboration platform. From version 2.6.0 to before version 4.3.0, when a previous collective pages was deleted and the collective was shared view-only, guests with access to the collective were able to access the deleted pages directly from the trashbin. This issue has been patched in version 4.3.0.

CVE-2026-45153 Medium · 4.6 CWE-287 Jun 1, 2026

Nextcloud: PIN bypass in PassCodeActivity via back button

Nextcloud is an open source content collaboration platform. From version 33.0.0 to before version 33.1.0, after unlocking a locked Android phone the back-button could be used to bypass the Nextcloud Files app PIN. This issue has been patched in version 33.1.0.

CVE-2026-44515 Low · 2.3 CWE-918 May 14, 2026

Nextcloud News: Authenticated blind SSRF via feed URL

Nextcloud News is an RSS/Atom feed reader. Prior to 28.3.0-beta.1, Nextcloud News allows authenticated users to add feeds by providing a feed URL (via the web interface or the API). In affected versions, an authenticated attacker could provide a URL pointing to internal/private IP ranges or localhost, causing the Nextcloud server to perform server-side HTTP requests to attacker-controlled destinations, but not relaying the result. This enables blind SSRF, which can be used to scan or probe internal network services that are reachable from the Nextcloud server. This vulnerability is fixed in 28.3.0-beta.1.

CVE-2026-22683 High · 8.8 Public exploit CWE-862 Apr 7, 2026

Windmill < 1.615.0 Operator Role Missing Authorization Checks RCE

Windmill versions 1.56.0 through 1.614.0 contain a missing authorization vulnerability that allows users with the Operator role to perform prohibited entity creation and modification actions via the backend API. Although Operators are documented and priced as unable to create or modify entities, the API does not enforce the Operator restriction on workspace endpoints, allowing an Operator to create and update scripts, flows, apps, and raw_apps. Since Operators can also execute scripts via the jobs API, this allows direct privilege escalation to remote code execution within the Windmill deployment. This vulnerability has existed since the introduction of the Operator role in version 1.56.0.

CVE-2025-64011 Medium · 4.3 CWE-639 Dec 12, 2025

Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core...

Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.

CVE-2025-66558 Medium · 4.3 CWE-639 Dec 5, 2025

Nextcloud Twofactor WebAuthn app was updated based on public key

Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols. The victim would then be prompted to register a new device on the next login. The attacker can not authenticate as the victim. This vulnerability is fixed in 1.4.2 and 2.4.1.

CVE-2025-66557 Medium · 4.3 CWE-284 Dec 5, 2025

Nextcloud Deck app allowed user with "Can share" permission to modify permissions of other non-owners

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.14.6 and 1.15.2, a bug in the permission logic allowed users with "Can share" permission to modify the permissions of other recipients. This vulnerability is fixed in 1.14.6 and 1.15.2.

CVE-2025-66556 Medium · 4.3 CWE-639 Dec 5, 2025

Nextcloud talk allows participants to blindly delete poll drafts of other users by ID

Nextcloud talk is a video & audio conferencing app for Nextcloud. Prior to 20.1.8 and 21.1.2, a participant with chat permissions was able to delete poll drafts of other participants within the conversation based on their numeric ID. This vulnerability is fixed in 20.1.8 and 21.1.2.

CVE-2025-66554 Medium · 5.4 CWE-79 Dec 5, 2025

Nextcloud Contacts vulnerable to Stored XSS in contacts app via organisation and title field

Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. Prior to 5.5.4, 6.0.6, and 7.2.5, a malicious user was able to modify their organisation and title field to load additional CSS files. Javascript and other options were correctly blocked by the content security policy of the Nextcloud Server code. This vulnerability is fixed in 5.5.4, 6.0.6, and 7.2.5.

CVE-2025-66553 Medium · 4.3 CWE-639 Dec 5, 2025

Nextcloud Tables app allowed users to view columns metadata information of any table

Nextcloud Tables allows you to create your own tables with individual columns. Prior to 0.8.7 and 0.9.4, authenticated users were able to view meta data of columns in other tables of the Tables app by modifying the numeric ID in a request. This vulnerability is fixed in 0.8.7 and 0.9.4.

CVE-2025-66551 Medium · 4.3 CWE-639 Dec 5, 2025

Nextcloud Tables is missing an ownership check which allows moving columns into tables of other users

Nextcloud Tables allows you to create your own tables with individual columns. Prior to 0.8.6 and 0.9.3, a malicious user was able to create their own table and then move a column to a victims table. This vulnerability is fixed in 0.8.6 and 0.9.3.

CVE-2025-66549 Low · 2.7 CWE-209 Dec 5, 2025

Nextcloud Desktop discloses information when attempting to lock a file inside a end-to-end encrypted directory

Nextcloud Desktop is the desktop sync client for Nextcloud. Prior to 3.16.5, when trying to manually lock a file inside an end-to-end encrypted directory, the path of the file was sent to the server unencrypted, making it possible for administrators to see it in log files. This vulnerability is fixed in 3.16.5.

CVE-2025-66548 Medium · 5.5 CWE-116 Dec 5, 2025

Nextcloud Deck app allows to spoof file extensions by using RTLO characters

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.12.7, 1.14.4, and 1.15.1, file extension can be spoofed by using RTLO characters, tricking users into download files with a different extension than what is displayed. This vulnerability is fixed in 1.12.7, 1.14.4, and 1.15.1.

CVE-2025-66545 Medium · 4.3 CWE-707 Dec 5, 2025

Nextcloud Groupfolders users with read-only permissions for team folder can restore deleted files from trash bin

Nextcloud Groupfolders provides admin-configured folders shared by everyone in a group or team. Prior to 14.0.11, 15.3.12, 16.0.15, 17.0.14, 18.1.8, 19.1.8, and 20.1.2, a user with read-only permission can restore a file from the trash bin. This vulnerability is fixed in 14.0.11, 15.3.12, 16.0.15, 17.0.14, 18.1.8, 19.1.8, and 20.1.2.

CVE-2025-66515 Low · 2.7 CWE-287 Dec 5, 2025

Nextcloud Approval app allows users to request approval for other users file

The Nextcloud Approval app allows approval or disapproval of files in the sidebar. Prior to 1.3.1 and 2.5.0, an authenticated user listed as a requester in a workflow can set another user’s file into the “pending approval” without access to the file by using the numeric file id. This vulnerability is fixed in 1.3.1 and 2.5.0.

CVE-2025-66514 Medium · 5.4 CWE-79 Dec 5, 2025

Nextcloud Mail stored HTML injection in subject text

Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform. Prior to 5.5.3, a stored HTML injection in the Mail app's message list allowed an authenticated user to inject HTML into the email subjects. Javascript was correctly blocked by the content security policy of the Nextcloud Server code.

CVE-2025-66513 Medium · 5.3 CWE-639 Dec 5, 2025

Nextcloud Tables app share information not limited to relevant users

Nextcloud Tables allows you to create your own tables with individual columns. Prior to 0.8.9, 0.9.6, and 1.0.1, the information which table (numeric ID) is shared with which groups or users and the respective permissions was not limited to privileged users. This vulnerability is fixed in 0.8.9, 0.9.6, and 1.0.1.