CVE-2026-6046 - Plugin bot username conflict allows user account to be used as bot identity in Mattermost Server
CVE ID :CVE-2026-6046
Published : June 12, 2026, 5:16 p.m. | 29 minutes ago
Description :Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to validate that a username returned during bot registration belongs to a bot account, which allows an unprivileged attacker to intercept private messages sent by plugins via direct message channels by pre-registering a user account with a predictable plugin bot username.. Mattermost Advisory ID: MMSA-2026-00649
Severity: 5.3 | MEDIUM
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Published : June 12, 2026, 5:16 p.m. | 29 minutes ago
Description :Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to validate that a username returned during bot registration belongs to a bot account, which allows an unprivileged attacker to intercept private messages sent by plugins via direct message channels by pre-registering a user account with a predictable plugin bot username.. Mattermost Advisory ID: MMSA-2026-00649
Severity: 5.3 | MEDIUM
Visit the link for more details, such as CVSS details, affected products, timeline, and more...