PT-2026-43013 · Mattermost · Mattermost

Daw10

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Published

2026-05-25

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Updated

2026-05-25

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CVE-2026-4915

CVSS v3.1

6.5

Medium

VectorAV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to filter nil elements from outgoing webhook attachment payloads before processing, which allows an authenticated user to cause a denial of service (server process termination) via a crafted webhook callback response containing a null attachment entry.. Mattermost Advisory ID: MMSA-2026-00641

Fix

Improper Check for Exceptional Conditions

Weakness Enumeration

Related Identifiers

CVE-2026-4915

Affected Products

Mattermost