Back to Database
Status published
Medium
CVE-2021-37865
Server-side Denial of Service while processing a specifically crafted GIF file
Vulnerability Description
Mattermost 6.2 and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded while drafting a post, which allows authenticated users to cause resource exhaustion while processing the file, resulting in server-side Denial of Service.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
THREAT MONITOR
Am I Vulnerable?
Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2021-37865
Credits & Attribution
No credits recorded in the NVD database.
More from Mattermost
View All →CVE-2025-9084
Open redirect in OAuth login
Low
3.1
CVE-2025-9081
IDOR in board file download allows any user to download any file by UUID
Low
3.1
CVE-2025-9079
Admin RCE via prepackaged plugins by way of misconfigured imports directory
High
8
CVE-2025-9078
Weak cache keys lead to post IDOR and link preview poisoning
Medium
4.3
CVE-2025-9076
Mattermost Server exposes sensitive user credentials during shared channel membership synchronization
Medium
6.5
Affected Vendor
Mattermost
View all reports →Affected Software
Mattermost
Vulnerable Versions:
unspecified, 6.1.1, 6.0.4, 5.39.3, 5.37.6
Timeline
Official Publish:
January 18th, 2022
Last Modified:
December 6th, 2024
Added to House:
July 21st, 2026
CVSS Vectors
V3:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L