A vulnerability classified as problematic has been found in Mattermost up to 10.11.10/11.2.2/11.3.0. This issue affects some unknown processing of the component Header Handler. The manipulation of the argument User-Agent leads to improper validation of specified type of input.
This vulnerability is referenced as CVE-2026-25783. Remote exploitation of the attack is possible. No exploit is available.
It is recommended to upgrade the affected component.
