CVE-2026-9699 — Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors

CVE-2026-9699

Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors PUBLISHED

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 0 through 10.18.11; affected 0 through 11.3.6; affected 0 through 11.6.5; unaffected 11.7.0; unaffected 10.11.19; unaffected 11.6.4; unaffected 11.5.7

CWE

CWE-532

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.