CVE-2024-1953

Mattermost versions 8.1.x before 8.1.9, 9.2.x before 9.2.5, 9.3.0, and 9.4.x before 9.4.2 fail to limit the number of role names requested from the API, allowing an authenticated attacker to cause the server to run out of memory and crash by issuing an unusually large HTTP request.

CVE-2024-23488

Mattermost fails to properly restrict the access of files attached to posts in an archived channel, resulting in members being able to access files of archived channels even if the “Allow users to view archived channels” option is disabled.

CVE-2024-1887

Mattermost fails to check if compliance export is enabled when fetching posts of public channels allowing a user that is not a member of the public channel to fetch the posts, which will not be audited in the compliance export.

CVE-2024-1942

Mattermost versions 8.1.x before 8.1.9, 9.2.x before 9.2.5, and 9.3.0 fail to sanitize the metadata on posts containing permalinks under specific conditions, which allows an authenticated attacker to access the contents of individual posts in channels they are not a member of.

CVE-2024-1888

Mattermost fails to check the "invite_guest" permission when inviting guests of other teams to a team, allowing a member with permissions to add other members but not to add guests to add a guest to a team as long as the guest was already a guest in another team of the server

CVE-2024-24776

Mattermost fails to check the required permissions in the POST /api/v4/channels/stats/member_count API resulting in channel member counts being leaked to a user without permissions.

CVE-2023-48732

Mattermost fails to scope the WebSocket response around notified users to a each user separately resulting in the WebSocket broadcasting the information about who was notified about a post to everyone else in the channel.

CVE-2023-47858

Mattermost fails to properly verify the permissions needed for viewing archived public channels, allowing a member of one team to get details about the archived public channels of another team via the GET /api/v4/teams/<team-id>/channels/deleted endpoint.

CVE-2024-1402

Mattermost fails to check if a custom emoji reaction exists when sending it to a post and to limit the amount of custom emojis allowed to be added in a post, allowing an attacker sending a huge amount of non-existent custom emojis in a post to crash the mobile app of a user seeing the post and to c...

CVE-2024-46872

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1, 9.5.x <= 9.5.9 fail to sanitize user inputs in the frontend that are used for redirection which allows for a one-click client-side path traversal that is leading to CSRF in Playbooks

CVE-2023-50333

Mattermost fails to update the permissions of the current session for a user who was just demoted to guest, allowing freshly demoted guests to change group names.

CVE-2024-1952

Mattermost version 8.1.x before 8.1.9 fails to sanitize data associated with permalinks when a plugin updates an ephemeral post, allowing an authenticated attacker who can control the ephemeral post update to access individual posts' contents in channels they are not a member of.

CVE-2024-42000

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1, 9.5.x <= 9.5.9 and 10.0.x <= 10.0.0 fail to properly authorize the requests to /api/v4/channels which allows a User or System Manager, with "Read Groups" permission but with no access for channels to retrieve details about private ...

CVE-2022-1332

One of the API in Mattermost version 6.4.1 and earlier fails to properly protect the permissions, which allows the authenticated members with restricted custom admin role to bypass the restrictions and view the server logs and server config.json file contents.

CVE-2024-29221

Improper Access Control in Mattermost Server versions 9.5.x before 9.5.2, 9.4.x before 9.4.4, 9.3.x before 9.3.3, 8.1.x before 8.1.11 lacked proper access control in the /api/v4/users/me/teams endpoint allowing a team admin to get the invite ID of their team, thus allowing them to invite users, eve...

CVE-2024-32046

Mattermost versions 9.6.x <= 9.6.0, 9.5.x <= 9.5.2, 9.4.x <= 9.4.4 and 8.1.x <= 8.1.11 fail to remove detailed error messages in API requests even if the developer mode is off which allows an attacker to get information about the server such as the full path were files are stored

CVE-2024-36250

Mattermost versions 9.11.x <= 9.11.2, and 9.5.x <= 9.5.10 fail to protect the mfa code against replay attacks, which allows an attacker to reuse the MFA code within ~30 seconds

CVE-2024-29215

Mattermost versions 9.5.x <= 9.5.3, 9.7.x <= 9.7.1, 9.6.x <= 9.6.1, 8.1.x <= 8.1.12 fail to enforce proper access control which allows a user to run a slash command in a channel they are not a member of via linking a playbook run to that channel and running a slash command as a playbook...

CVE-2024-41162

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow the modification of local channels by a remote, when shared channels are enabled, which allows a malicious remote to make an arbitrary local channel read-only.

CVE-2023-2281

When archiving a team, Mattermost fails to sanitize the related Websocket event sent to currently connected clients. This allows the clients to see the name, display name, description, and other data about the archived team.

CVE-2024-4182

Mattermost versions 9.6.0, 9.5.x before 9.5.3, 9.4.x before 9.4.5, and 8.1.x before 8.1.12 fail to handle JSON parsing errors in custom status values, which allows an authenticated attacker to crash other users' web clients via a malformed custom status.

CVE-2024-2446

Mattermost versions 8.1.x before 8.1.10, 9.2.x before 9.2.6, 9.3.x before 9.3.2, and 9.4.x before 9.4.3 fail to limit the number of @-mentions processed per message, allowing an authenticated attacker to crash the client applications of other users via large, crafted messages.

CVE-2024-41926

Mattermost versions 9.9.x <= 9.9.0 and 9.5.x <= 9.5.6 fail to validate the source of sync messages and only allow the correct remote IDs, which allows a malicious remote to set arbitrary RemoteId values for synced users and therefore claim that a user was synced from another remote.

CVE-2024-52032

Mattermost versions 10.0.x <= 10.0.0 and 9.11.x <= 9.11.2 fail to properly query ElasticSearch when searching for the channel name in channel switcher which allows an attacker to get private channels names of channels that they are not a member of, when Elasticsearch v8 was enabled.

CVE-2025-24920

Mattermost versions 10.4.x <= 10.4.2, 10.3.x <= 10.3.3, 9.11.x <= 9.11.8, 10.5.x <= 10.5.0 fail to restrict bookmark creation and updates in archived channels, which allows authenticated users created or update bookmarked in archived channels

CVE-2016-11081

An issue was discovered in Mattermost Server before 2.2.0. It allows unintended access to information stored by a web browser.

CVE-2024-39839

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5, 9.8.x <= 9.8.1 fail to disallow users to set their own remote username, when shared channels were enabled, which allows a user on a remote to set their remote username prop to an arbitrary string, which would be then sy...

CVE-2025-3611

Mattermost versions 10.7.x <= 10.7.0, 10.5.x <= 10.5.3, 9.11.x <= 9.11.12 fails to properly enforce access control restrictions for System Manager roles, allowing authenticated users with System Manager privileges to view team details they should not have access to via direct API requests ...

CVE-2024-47145

Mattermost versions 9.5.x <= 9.5.8 fail to properly authorize access to archived channels when viewing archived channels is disabled, which allows an attacker to view posts and files of archived channels via file links.

CVE-2018-21254

An issue was discovered in Mattermost Server before 5.1. An attacker can bypass intended access control (for direct-message channel creation) via the Message slash command.

CVE-2024-43780

Mattermost versions 9.9.x <= 9.9.1, 9.5.x <= 9.5.7, 9.10.0, 9.8.x <= 9.8.2 fail to enforce permissions which allows a guest user with read access to upload files to a channel.

CVE-2025-4128

Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.

CVE-2025-4573

Mattermost versions 10.7.x <= 10.7.1, 10.6.x <= 10.6.3, 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly validate LDAP group ID attributes, allowing an authenticated administrator with PermissionSysconsoleWriteUserManagementGroups permission to execute LDAP search filter injection v...

CVE-2016-11077

An issue was discovered in Mattermost Server before 3.0.0. It has a superfluous API in which the System Admin can change the account name and e-mail address of an LDAP account.

CVE-2019-20887

An issue was discovered in Mattermost Server before 5.7.1, 5.6.4, 5.5.3, and 4.10.6. It does not honor flags API permissions when deciding whether a user can receive intra-team posts.

CVE-2016-11065

An issue was discovered in Mattermost Server before 3.3.0. An attacker could use the WebSocket feature to send pop-up messages to users or change a post's appearance.

CVE-2017-18890

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows an attacker to create a button that, when pressed by a user, launches an API request.

CVE-2018-21253

An issue was discovered in Mattermost Server before 5.1, 5.0.2, and 4.10.2. An attacker could use the invite_people slash command to invite a non-permitted user.

CVE-2018-21256

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for group-message channel creation) via the Group message slash command.

CVE-2024-24774

Mattermost Jira Plugin handling subscriptions fails to check the security level of an incoming issue or limit it based on the user who created the subscription resulting in registered users on Jira being able to create webhooks that give them access to all Jira issues.

CVE-2017-18876

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2 when local storage for files is used. A System Admin can test for the existence of an arbitrary file.

CVE-2016-11080

An issue was discovered in Mattermost Server before 3.0.0. It offers superfluous APIs for a Team Administrator to view account details.

CVE-2017-18918

An issue was discovered in Mattermost Server before 3.7.3 and 3.6.5. A System Administrator can place a SAML certificate at an arbitrary pathname.

CVE-2019-20879

An issue was discovered in Mattermost Server before 5.8.0, 5.7.2, 5.6.5, and 4.10.7. Changes to e-mail addresses do not require credential re-entry.

CVE-2017-18878

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. Knowledge of a session ID allows revoking another user's session.

CVE-2017-18889

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. An attacker could create fictive system-message posts via webhooks and slash commands, in the v3 or v4 REST API.

CVE-2019-20883

An issue was discovered in Mattermost Server before 5.8.0, when Town Square is set to Read-Only. Users can pin or unpin a post.

CVE-2023-3582

Mattermost fails to verify channel membership when linking a board to a channel allowing a low-privileged authenticated user to link a Board to a private channel they don't have access to,

CVE-2017-18870

An issue was discovered in Mattermost Server before 4.5.0, 4.4.5, and 4.3.4. It mishandled webhook access control in the EnableOnlyAdminIntegrations case.

CVE-2017-18875

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2 when local storage for files is used. A System Admin can create arbitrary files.