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Vendor Solution
Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8, 10.11.23 or higher.
Tracking
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No advisories yet.
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
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Mon, 14 Sep 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mattermost
Mattermost mattermost |
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| Vendors & Products |
Mattermost
Mattermost mattermost |
Mon, 14 Sep 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 14 Sep 2026 11:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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 validate null entries in Microsoft Graph webhook notification payloads, which allows an unauthenticated attacker to crash the Microsoft Calendar plugin process and deny calendar integration service to all users on the instance via a crafted {{POST}} request to the public webhook endpoint.. Mattermost Advisory ID: MMSA-2026-00693 | |
| Title | Unauthenticated webhook request with null notification entry could crash the Microsoft Calendar plugin. | |
| Weaknesses | CWE-754 | |
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: Mattermost
Published:
Updated: 2026-09-14T11:19:44.241Z
Reserved: 2026-06-01T14:36:14.113Z
Link: CVE-2026-10556
Updated: 2026-09-14T11:13:22.629Z
Status : Received
Published: 2026-09-14T11:17:02.590
Modified: 2026-09-14T12:17:37.917
Link: CVE-2026-10556
No data.
OpenCVE Enrichment
Updated: 2026-09-14T14:00:04Z
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CWE-754
Improper Check for Unusual or Exceptional Conditions