CVE-2026-16251
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to limit the size of remote image responses buffered in memory during local image proxy direct fetches, which allows a remote attacker to cause memory exhaustion on the server via a crafted oversized image response.. Mattermost Advisory ID: MMSA-2026-00726
Published:Oct 16, 2026
Last Modified:Oct 29, 2026
EPS:Oct 16, 2026
EPSS Score:0.0028
CVSS Score:6.5
Affected Products
Vendor
Product
Action
Vendor
Mattermost
Product
Mattermost
Mattermost
Mattermost
Vendor
Mattermost
Product
Mattermost Server
Mattermost
Mattermost Server
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
