CVE-2025-49222

Mattermost Shared Channel Upload Type Validation Bypass

Description

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.9.x <= 10.9.2, 10.10.x <= 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in arbitrary filesystem directories.

Remediation

Solution:

  • Update Mattermost to versions 10.11.0, 10.8.4, 10.5.9, 9.11.18, 10.9.3, 10.10.1 or higher.

Category

6.8
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.03%
Affected: Mattermost Mattermost
Published at:
Updated at:

References

Link Tags
https://mattermost.com/security-updates

Frequently Asked Questions

What is the severity of CVE-2025-49222?
CVE-2025-49222 has been scored as a medium severity vulnerability.
How to fix CVE-2025-49222?
To fix CVE-2025-49222: Update Mattermost to versions 10.11.0, 10.8.4, 10.5.9, 9.11.18, 10.9.3, 10.10.1 or higher.
Is CVE-2025-49222 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-49222 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-49222?
CVE-2025-49222 affects Mattermost Mattermost.
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