Medium severity · published Feb 16, 2026
CVE-2026-0998
Mattermost Zoom Plugin allows unauthorized meeting creation and post modification via insufficient API access controls
4.3
CVSS
0.2%
EPSS
No
On KEV
Description
Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 and Mattermost Plugin Zoom versions <=1.11.0 fail to validate user identity and post ownership in the {{/api/v1/askPMI}} endpoint which allows unauthorized users to start Zoom meetings as any user and overwrite arbitrary posts via direct API calls with manipulated user IDs and post data.. Mattermost Advisory ID: MMSA-2025-00534
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Mattermost · Mattermost
11.1.0 through 11.1.2; 10.11.0 through 10.11.9; 11.2.0 through 11.2.1 · source: vendor
MS
Mattermost Server · Mattermost
10.11.0 before 10.11.10; 11.1.0 before 11.1.3; 11.2.0 before 11.2.2 · source: NVD
ZO
Zoom · Mattermost
through 1.11.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-0998
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-0998
Vendor Advisory
https://mattermost.com/security-updates
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