CVE-2026-9699
Mattermost Agents plugin logs unsanitized OpenAI API keys on authentication errors
Description
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
INFO
Published Date :
June 26, 2026, 2:43 p.m.
Last Modified :
June 26, 2026, 2:43 p.m.
Remotely Exploit :
Yes !
Source :
Mattermost
Affected Products
The following products are affected by CVE-2026-9699
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 9302f53e-dde5-4bf3-b2f2-a83f91ac0eee |
Solution
- Update Mattermost plugins to version 11.6.5.0 or later.
- Sanitize error responses from the OpenAI API.
- Review server logs for exposed API keys.
- Rotate compromised OpenAI API keys.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-9699 vulnerability anywhere in the article.