{"id":"CVE-2026-9699","aliases":["EUVD-2026-39778","GHSA-gr4w-63r3-8h38"],"status":"published","title":"Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors","description":"Mattermost Plugins versions \u003c=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","severity":{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00459,"percentile":0.4012,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-532"],"published":"2026-06-26T14:43:51Z","modified":"2026-06-26T16:16:37Z","products":[{"vendor":"mattermost","product":"mattermost"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9699"},{"url":"https://github.com/advisories/GHSA-gr4w-63r3-8h38"}],"sources":{"cve":[{"id":"CVE-2026-9699","title":"Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-06-26T14:43:51.702Z","modified":"2026-06-26T15:40:52.251Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-532"],"updated_at":"2026-11-02T13:42:37.965383Z"}],"euvd":[{"id":"EUVD-2026-39778","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-06-26T14:43:51Z","modified":"2026-06-26T15:40:52Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:20:24.495602Z"}],"ghsa":[{"id":"GHSA-gr4w-63r3-8h38","title":"Mattermost Plugins versions \u003c=11.6 10.18.11 11.3.6 11.6.5.0 fail to sanitize error responses from...","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-06-26T15:32:18Z","modified":"2026-06-26T15:32:30Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-532"],"updated_at":"2026-11-02T15:09:01.181648Z"}],"nvd":[{"id":"CVE-2026-9699","description":"Mattermost Plugins versions \u003c=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","status":"published","published":"2026-06-26T15:16:56.083Z","modified":"2026-06-26T16:16:37.36Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-532"],"updated_at":"2026-11-02T14:12:26.045561Z"}]}}