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435 vulnerabilities found for Mattermost by Mattermost
CVE-2026-75587 (GCVE-0-2026-75587)
Vulnerability from cvelistv5
Published
2026-08-17 22:09
Modified
2026-08-18 14:20
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
Summary
Mattermost Desktop App versions <=6.2 6.2.2.0 fail to redact the pre-auth secret when generating a diagnostics report, which allows a local attacker with access to a user's diagnostics report or log files to obtain the plaintext pre-auth secret configured for a connected server via inspecting the Server Connectivity (Step-3) diagnostics output. Mattermost Advisory ID: MMSA-2026-00716
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 0 ≤ 6.2.2 |
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CVE-2026-9693 (GCVE-0-2026-9693)
Vulnerability from cvelistv5
Published
2026-08-17 22:07
Modified
2026-08-18 14:21
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-459 - Incomplete Cleanup
Summary
Mattermost versions 10.11.x <= 10.11.20, 11.7.x <= 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via the team threads API.. Mattermost Advisory ID: MMSA-2026-00682
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 10.11.0 ≤ 10.11.20 Version: 11.7.0 ≤ 11.7.5 |
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CVE-2026-9859 (GCVE-0-2026-9859)
Vulnerability from cvelistv5
Published
2026-08-17 22:06
Modified
2026-08-18 14:22
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoint, which allows an authenticated board editor to relink any board they can edit to an arbitrary channel via a crafted PATCH request. Mattermost Advisory ID: MMSA-2026-00686
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 Version: 11.8.0 ≤ 11.8.3 |
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CVE-2026-9816 (GCVE-0-2026-9816)
Vulnerability from cvelistv5
Published
2026-08-17 22:05
Modified
2026-08-18 15:26
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate BoardMember.Scheme* fields server-side on insert and archive-import paths which allows a board editor or non-guest team member to grant board admin to arbitrary users via POST /api/v2/boards/{boardID}/members and POST /api/v2/teams/{teamID}/archive/import.. Mattermost Advisory ID: MMSA-2026-00685
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 Version: 11.8.0 ≤ 11.8.3 |
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CVE-2026-10080 (GCVE-0-2026-10080)
Vulnerability from cvelistv5
Published
2026-08-17 22:04
Modified
2026-08-18 15:23
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-704 - Incorrect Type Conversion or Cast
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to validate WebSocket command field types which allows an authenticated user to crash the plugin process and deny service to all Boards users via a custom_focalboard_SUBSCRIBE_TEAM message with a non-string teamId.. Mattermost Advisory ID: MMSA-2026-00687
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 Version: 11.8.0 ≤ 11.8.3 |
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CVE-2026-10527 (GCVE-0-2026-10527)
Vulnerability from cvelistv5
Published
2026-08-17 14:37
Modified
2026-08-17 15:25
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 Version: 11.8.0 ≤ 11.8.3 |
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CVE-2026-15754 (GCVE-0-2026-15754)
Vulnerability from cvelistv5
Published
2026-08-17 14:36
Modified
2026-08-17 15:25
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 11.8.x <= 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belongs to the requesting admin's team, which allows an authenticated team administrator to remove ABAC (attribute-based access control) policy assignments from channels outside their team via the policy unassign API after a channel has been moved to another team.. Mattermost Advisory ID: MMSA-2026-00718
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 11.8.0 ≤ 11.8.3 |
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CVE-2026-16044 (GCVE-0-2026-16044)
Vulnerability from cvelistv5
Published
2026-08-17 14:26
Modified
2026-08-17 15:25
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 |
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CVE-2026-16045 (GCVE-0-2026-16045)
Vulnerability from cvelistv5
Published
2026-08-17 14:26
Modified
2026-08-17 15:26
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 Mattermost failed to restrict OAuth deauthorization and personal access token management endpoints to direct user sessions, which allowed an OAuth app with a delegated user token to revoke the user's authorizations or tokens for other integrations via account-management endpoints.. Mattermost Advisory ID: MMSA-2026-00704
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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CVE-2026-16049 (GCVE-0-2026-16049)
Vulnerability from cvelistv5
Published
2026-08-17 14:25
Modified
2026-08-17 15:26
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-862 - Missing Authorization
Summary
Mattermost Plugins versions <=11.8 10.20.11 11.5.7.0 _The Mattermost GitLab plugin fails to verify channel permissions when processing API requests with a caller-supplied_ {{post_id}}_, and fails to validate the_ {{web_url}} _parameter against the configured GitLab instance, which allows an authenticated attacker to inject bot-authored messages containing arbitrary URLs into channels they do not have access to via the_ {{createIssue}} _and_ {{attachCommentToIssue}} _API endpoints._ Mattermost Advisory ID: MMSA-2026-00673
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 0 ≤ 10.20.11 Version: 0 ≤ 11.5.7 |
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CVE-2026-16047 (GCVE-0-2026-16047)
Vulnerability from cvelistv5
Published
2026-08-17 14:25
Modified
2026-08-17 15:26
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-862 - Missing Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate that users have read access to a channel before linking a board to it, which allows an authenticated attacker to discover the membership of private channels on the same team via creating, patching, importing, or bulk-creating boards with an arbitrary channelId. Mattermost Advisory ID: MMSA-2026-00674
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 Version: 11.8.0 ≤ 11.8.3 |
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CVE-2026-16046 (GCVE-0-2026-16046)
Vulnerability from cvelistv5
Published
2026-08-17 14:24
Modified
2026-08-18 13:22
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to enforce run-state validation on write operations for finished playbook runs which allows a run participant to modify status, checklists, retrospective content, ownership, and participants on completed runs via REST and GraphQL API requests. Mattermost Advisory ID: MMSA-2026-00675
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 |
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CVE-2026-16048 (GCVE-0-2026-16048)
Vulnerability from cvelistv5
Published
2026-08-17 14:22
Modified
2026-08-17 15:37
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to restrict channel member role assignment to channel-scoped roles which allows a channel administrator to gain additional channel permissions via the channel member roles API.. Mattermost Advisory ID: MMSA-2026-00697
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.8.0 ≤ 11.8.2 Version: 11.7.0 ≤ 11.7.6 Version: 10.11.0 ≤ 10.11.21 |
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CVE-2026-14298 (GCVE-0-2026-14298)
Vulnerability from cvelistv5
Published
2026-08-13 08:03
Modified
2026-08-13 14:16
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly limit resource consumption when processing certain user-supplied input, which allows an authenticated user to cause a denial of service. Mattermost Advisory ID: MMSA-2026-00713
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.9.0 ≤ 11.9.0 Version: 11.8.0 ≤ 11.8.4 Version: 11.7.0 ≤ 11.7.7 Version: 10.11.0 ≤ 10.11.22 |
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CVE-2026-7521 (GCVE-0-2026-7521)
Vulnerability from cvelistv5
Published
2026-07-28 13:58
Modified
2026-07-28 14:48
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Summary
Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to verify file deletion path which allows an admin with SAML system-console write permissions to delete arbitrary files outside the config directory from the server via the remove file endpoint.. Mattermost Advisory ID: MMSA-2026-00666
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.8.0 ≤ 11.8.0 Version: 11.7.0 ≤ 11.7.3 Version: 11.6.0 ≤ 11.6.5 Version: 10.11.0 ≤ 10.11.20 |
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CVE-2026-10819 (GCVE-0-2026-10819)
Vulnerability from cvelistv5
Published
2026-07-27 14:15
Modified
2026-07-27 15:05
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Summary
Mattermost versions 11.6.x <= 11.6.5, 10.11.x <= 10.11.20, 11.8.x <= 11.8.1, 11.7.x <= 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom emoji.. Mattermost Advisory ID: MMSA-2026-00695
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.6.0 ≤ 11.6.5 Version: 10.11.0 ≤ 10.11.20 Version: 11.8.0 ≤ 11.8.1 Version: 11.7.0 ≤ 11.7.4 |
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CVE-2026-10600 (GCVE-0-2026-10600)
Vulnerability from cvelistv5
Published
2026-07-27 14:13
Modified
2026-07-27 15:04
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server via repeatedly uploading small documents that are cheap to upload but expensive to extract, saturating the shared extraction worker pool.. Mattermost Advisory ID: MMSA-2026-00694
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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CVE-2026-8075 (GCVE-0-2026-8075)
Vulnerability from cvelistv5
Published
2026-07-17 10:05
Modified
2026-07-17 12:53
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Summary
Mattermost Desktop App versions <=6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermost Advisory ID: MMSA-2026-00668
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 0 ≤ 5.5.13 Version: 0 ≤ 6.0.2 |
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CVE-2026-9602 (GCVE-0-2026-9602)
Vulnerability from cvelistv5
Published
2026-07-17 10:03
Modified
2026-07-17 12:54
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-400 - Uncontrolled Resource Consumption
Summary
Mattermost Desktop App versions <=6.2 6.0.2 5.6.13.0 fail to validate payloads sent from the Mattermost Web App to the Desktop App which allows a malicious server owner to crash the Mattermost Desktop App via changing the payload of a method to a malformed one. Mattermost Advisory ID: MMSA-2026-00678
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 0 ≤ 6.0.2 Version: 0 ≤ 5.6.13 |
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CVE-2026-6541 (GCVE-0-2026-6541)
Vulnerability from cvelistv5
Published
2026-07-13 10:53
Modified
2026-07-13 13:09
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Summary
Mattermost versions 11.7.x <= 11.7.1, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to restrict metric configuration changes to the playbook being saved, which allows an authenticated user with team access to alter another user’s playbook metric settings via a crafted import or update request with a foreign metric ID. Mattermost Advisory ID: MMSA-2026-00653
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.1 Version: 11.6.0 ≤ 11.6.4 Version: 10.11.0 ≤ 10.11.19 |
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CVE-2026-9820 (GCVE-0-2026-9820)
Vulnerability from cvelistv5
Published
2026-07-13 10:51
Modified
2026-07-13 13:09
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-862 - Missing Authorization
Summary
Mattermost versions 11.7.x <= 11.7.2, 10.11.x <= 10.11.19 fail to sanitize team objects returned by the scheme teams endpoint, which allows a user with the User Manager role to obtain invite links for private teams and use them to join or share access to those teams via the scheme teams API endpoint.. Mattermost Advisory ID: MMSA-2026-00671
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.2 Version: 10.11.0 ≤ 10.11.19 |
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CVE-2026-9824 (GCVE-0-2026-9824)
Vulnerability from cvelistv5
Published
2026-07-13 10:47
Modified
2026-07-13 13:10
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-862 - Missing Authorization
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to check the manage_shared_channels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash command autocomplete.. Mattermost Advisory ID: MMSA-2026-00676
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.2 Version: 11.6.0 ≤ 11.6.4 Version: 10.11.0 ≤ 10.11.19 |
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CVE-2026-9597 (GCVE-0-2026-9597)
Vulnerability from cvelistv5
Published
2026-07-13 08:17
Modified
2026-07-13 13:55
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-305 - – Authentication Bypass by Primary Weakness
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.2 Version: 11.6.0 ≤ 11.6.4 |
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CVE-2026-6850 (GCVE-0-2026-6850)
Vulnerability from cvelistv5
Published
2026-07-13 08:13
Modified
2026-07-13 13:56
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to validate the length and content of message attachment field values, which allows an authenticated attacker to cause a denial of service for all users in a channel via a post containing a specially crafted payload that triggers catastrophic backtracking in the client-side markdown parser.. Mattermost Advisory ID: MMSA-2026-00658
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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CVE-2026-10106 (GCVE-0-2026-10106)
Vulnerability from cvelistv5
Published
2026-07-13 08:09
Modified
2026-07-13 13:56
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-863 - Incorrect Authorization
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify that the channel referenced in an action cookie matches the channel of the target post, which allows an authenticated user without access to a private channel to trigger interactive post actions on posts in that channel via a cookie obtained from any accessible channel.. Mattermost Advisory ID: MMSA-2026-00690
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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CVE-2026-10085 (GCVE-0-2026-10085)
Vulnerability from cvelistv5
Published
2026-07-13 08:05
Modified
2026-07-13 13:57
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-862 - Missing Authorization
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to restrict the group_constrained channel flag to public and private channels that support group synchronization, which allows an ordinary group or direct message member to remove all participants from the conversation via the channel patch API.. Mattermost Advisory ID: MMSA-2026-00688
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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CVE-2026-9708 (GCVE-0-2026-9708)
Vulnerability from cvelistv5
Published
2026-07-13 08:00
Modified
2026-07-13 14:45
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to validate that an assigned incoming webhook user has access to the target team or channel, which allows a requester with webhook management permissions to create posts or direct messages attributed to another user via crafted incoming webhook configuration and payloads.. Mattermost Advisory ID: MMSA-2026-00683
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.2 Version: 11.6.0 ≤ 11.6.4 Version: 10.11.0 ≤ 10.11.19 |
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CVE-2026-10103 (GCVE-0-2026-10103)
Vulnerability from cvelistv5
Published
2026-07-13 07:57
Modified
2026-07-14 14:32
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing arbitrary post IDs in channels shared with that remote.. Mattermost Advisory ID: MMSA-2026-00689
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
Version: 11.7.0 ≤ 11.7.2 Version: 11.6.0 ≤ 11.6.4 Version: 10.11.0 ≤ 10.11.19 |
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CVE-2026-9571 (GCVE-0-2026-9571)
Vulnerability from cvelistv5
Published
2026-07-13 07:50
Modified
2026-07-15 04:00
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-305 - – Authentication Bypass by Primary Weakness
Summary
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to invalidate OAuth refresh tokens upon user account deactivation, which allows a deactivated user or an attacker in possession of a valid refresh token to obtain new functional access tokens via the OAuth refresh token grant endpoint.. Mattermost Advisory ID: MMSA-2026-00680
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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CVE-2026-4339 (GCVE-0-2026-4339)
Vulnerability from cvelistv5
Published
2026-06-26 14:44
Modified
2026-06-26 15:40
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-918 - Server-Side Request Forgery (SSRF)
Summary
Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to validate attachment URLs against internal or private IP ranges in the Mattermost Agents plugin MCP server which allows an attacker with access to the MCP server in stdio mode to perform server-side request forgery (SSRF) and exfiltrate data from internal network services via supplying internal URLs as file attachments in post creation requests.. Mattermost Advisory ID: MMSA-2026-00635
References
| URL | Tags | ||||
|---|---|---|---|---|---|
|
|||||
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Mattermost | Mattermost |
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"cveId": "CVE-2026-4339",
"datePublished": "2026-06-26T14:44:58.655Z",
"dateReserved": "2026-03-17T14:57:10.575Z",
"dateUpdated": "2026-06-26T15:40:33.300Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}