CVE-2026-9699CWE-532

Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors

Medium · published June 26, 2026

CVSS v3.1
6.8
EPSS
0%
Percentile
38.8
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
6.8 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00459 · 38.8th percentile
Weakness
CWE-532 · Insertion of Sensitive Information into Log File
Published
2026-06-26T14:43Z
EPSS history
Timeline
  • 26 JUN 14:43Z
    Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors
    cvelistv5