The vulnerability involves improper bounds checking during memory allocation when processing DOC files in Mattermost server. An authenticated attacker can craft a malicious DOC file that triggers excessive memory consumption, leading to server memory exhaustion and a denial‑of‑service condition. The weakness is identified by CWE-789, "Uncontrolled Memory Allocation."

Affected products are Mattermost Server versions 11.3.x (<= 11.3.0), 11.2.x (<= 11.2.2), and 10.11.x (<= 10.11.10) as listed by the CNA. The associated CPE is cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*.

The CVSS score of 4.3 indicates a medium severity but the EPSS score of less than 1% signals a very low probability of exploitation. The vulnerability is not present in the CISA KEV catalog. Exploitation requires a valid authenticated session and the upload of a crafted DOC file, which can be performed through the standard file‑upload interface of the Mattermost web or APIs.