Memory Consumption Vulnerability in Mattermost by Mattermost
CVE-2026-15814

6.5MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
14 September 2026

What is CVE-2026-15814?

Certain versions of Mattermost are vulnerable due to improper limitations on memory allocation when processing uploaded image files. This flaw can be exploited by authenticated users who upload specially crafted images as profile pictures, channel file attachments, team icons, or custom brand images. Successful exploitation can lead to excessive memory consumption, resulting in a denial of service, affecting the availability of the Mattermost service.

Affected Version(s)

Mattermost 11.9.0

Mattermost 11.8.0 <= 11.8.4

Mattermost 11.7.0 <= 11.7.7

References

https://mattermost.com/security-updates
vendor-advisory

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

alimursaliyev
.