Unauthenticated webhook request with null notification entry could crash the Microsoft Calendar plugin.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| Mattermost | Mattermost | unaffected |
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Configuration 1 [-]
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No data.
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| Mattermost | Mattermost |
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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.
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.420% probability within 30 days)
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| https://mattermost.com/security-updates |
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Mattermost mattermost Server
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| Weaknesses | CWE-476 | |
| CPEs | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | |
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Mattermost mattermost Server
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Mattermost
Mattermost mattermost |
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Mattermost
Mattermost mattermost |
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| Metrics |
ssvc
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| 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 | |
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| Metrics |
cvssV3_1
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