NetSight
medium6.5

CVE-2026-15814

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding upload…

Impact

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719

Affected products

VendorProductAffected versions
MattermostMattermost Server
from 10.11.0 before 10.11.23
from 11.7.0 before 11.7.8
from 11.8.0 before 11.8.5
from 11.9.0 before 11.9.1

Weakness classification

References