Is CVE-2026-9699 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-9699 being exploited in the wild.

How severe is CVE-2026-9699?

Medium severity, with a CVSS score of 6.8, published 26 June 2026.

Which products and versions are affected?

Mattermost Plugins <= 10.18.11, <= 11.3.6, <= 11.6.5.

Is there a fix for CVE-2026-9699?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-9699 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-9699?

Check whether you run Mattermost Plugins at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-9699: Mattermost Plugins sensitive information disclosure in OpenAI logging

Q: Which products and versions are affected?

Mattermost Plugins <= 10.18.11, <= 11.3.6, <= 11.6.5.

Q: Is there a fix for CVE-2026-9699?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

Q: How is CVE-2026-9699 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-9699?

Check whether you run Mattermost Plugins at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-9699 · Severity: medium · CVSS 6.8 · Published 2026-06-26

Mattermost plugins used for AI integration fail to properly hide sensitive credentials when recording system errors. This allows individuals with access to server logs or support diagnostic files to view OpenAI API keys, which could lead to unauthorized use of the organization's AI accounts and associated costs. Organizations should update their Mattermost plugins to the latest versions to ensure these keys are properly masked.

Technologies: Mattermost Plugins. Vendors: Mattermost.

Quick answers

Is CVE-2026-9699 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-9699 being exploited in the wild.
How severe is CVE-2026-9699?: Medium severity, with a CVSS score of 6.8, published 26 June 2026.
Which products and versions are affected?: Mattermost Plugins <= 10.18.11, <= 11.3.6, <= 11.6.5.
Is there a fix for CVE-2026-9699?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-9699 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-9699?: Check whether you run Mattermost Plugins at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A sensitive information disclosure vulnerability (CWE-532) exists in Mattermost Plugins due to insufficient sanitization of OpenAI API error responses. When authentication failures occur, the plugin logs the raw error response from OpenAI into the mattermost.log file or support packets. An attacker with high privileges (PR:H) or access to the server's file system can inspect these logs to recover or reconstruct valid OpenAI API keys. The vulnerability is addressed in versions 11.7.0, 10.11.19, 11.6.4, and 11.5.7.

Affected products

Mattermost Mattermost Plugins <= 10.18.11, <= 11.3.6, <= 11.6.5

Timeline

2026-06-26: disclosed
2026-06-26: advisory

References

https://mattermost.com/security-updates

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