CVE-2026-9699
Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors
CVSS Score
6.8
EPSS Score
0.0%
EPSS Percentile
0th
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
| CWE | CWE-532 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Jun 26, 2026 |
| Last Updated | Jun 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
Mattermost / Mattermost
0 ≤ 10.18.11 0 ≤ 11.3.6 0 ≤ 11.6.5
Credits
Edgar Bellot Micó