CVE-2026-9699Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
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
- CVSS
- 6.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
- Weakness (CWE)
- CWE-532
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Mattermost
- NVD analysis
- Awaiting Analysis
- Record last updated
- Jun 26, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mattermost Mattermost mattermost:mattermost (from the name) | through 10.18.11; through 11.3.6; through 11.6.5; 11.7.0 not affected; 10.11.19 not affected; 11.6.4 not affected; 11.5.7 not affected | CNA record |
References
- https://mattermost.com/security-updatesvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.