Mattermost Plugins versions <=11.6 10.18.11 11.3.6 11.6.5.0 fail to sanitize error responses from the OpenAI API before logging, which allows a user with access to server logs or support packets to obtain a valid or partially reconstructable OpenAI API key via inspection of mattermost.log entries generated during authentication failures. Mattermost Advisory ID: MMSA-2026-00609

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Fixes

Solution

Update Mattermost Plugins to versions 11.7.0, 10.11.19, 11.6.4, 11.5.7 or higher.


Workaround

No workaround given by the vendor.

References
History

Fri, 26 Jun 2026 21:15:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Fri, 26 Jun 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 26 Jun 2026 15:15:00 +0000

Type Values Removed Values Added
Description Mattermost Plugins versions <=11.6 10.18.11 11.3.6 11.6.5.0 fail to sanitize error responses from the OpenAI API before logging, which allows a user with access to server logs or support packets to obtain a valid or partially reconstructable OpenAI API key via inspection of mattermost.log entries generated during authentication failures. Mattermost Advisory ID: MMSA-2026-00609
Title Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors
Weaknesses CWE-532
References
Metrics cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-06-26T15:40:52.251Z

Reserved: 2026-05-27T12:08:53.502Z

Link: CVE-2026-9699

cve-icon Vulnrichment

Updated: 2026-06-26T15:40:48.396Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-26T21:00:05Z

Weaknesses