A vulnerability was found in Mattermost up to 10.11.14/11.4.4/11.5.3/11.6.0. It has been declared as problematic. Affected by this issue is some unknown functionality of the component Webhook Attachment Handler. Executing a manipulation can lead to improper check for unusual conditions.
This vulnerability is handled as CVE-2026-4915. The attack can be executed remotely. There is not any exploit available.
It is recommended to upgrade the affected component.
