Is CVE-2026-96260 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-96260 being exploited in the wild.

How severe is CVE-2026-96260?

Medium severity, with a CVSS score of 6.5, published 22 September 2026.

Which products and versions are affected?

Mattermost Server 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1.

Is there a fix for CVE-2026-96260?

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-2026-96260 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-96260?

Check whether you run Mattermost Server 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-2026-96260: Mattermost memory exhaustion in CSRF validation for plugin endpoints

Q: Is there a fix for CVE-2026-96260?

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-2026-96260 attacked?

It is attacked over the network, in a web application.

Q: Am I affected by CVE-2026-96260?

Check whether you run Mattermost Server 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-2026-96260 · Severity: medium · CVSS 6.5 · Published 2026-09-22

Mattermost, a team communication platform, fails to enforce request body size limits when validating plugin requests, allowing an authenticated user to send extremely large requests that exhaust server memory. An attacker with valid credentials can trigger a denial of service, making the communication platform unavailable to legitimate users.

Technologies: Mattermost Server. Vendors: Mattermost.

Quick answers

Is CVE-2026-96260 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-96260 being exploited in the wild.
How severe is CVE-2026-96260?: Medium severity, with a CVSS score of 6.5, published 22 September 2026.
Which products and versions are affected?: Mattermost Server 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1.
Is there a fix for CVE-2026-96260?: 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-2026-96260 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-96260?: Check whether you run Mattermost Server 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

The vulnerability exists in CSRF validation logic for plugin endpoints across affected versions, which does not enforce request body size limits before processing. An authenticated attacker can send a large request body to a plugin endpoint to exhaust server memory and cause denial of service. Patches are available in fixed versions for each affected release branch.

Affected products

Mattermost Mattermost Server 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1

Timeline

2026-09-22: disclosed

References

https://mattermost.com/security-updates

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