CVE-2026-6046

MEDIUM EPSS 8.8%
Published Jun 12, 20262w ago · Modified Jun 18, 20261w ago
5.3 CVSS 3.1
Medium
Find Similar
Published Jun 12, 2026 2w ago
Last Modified Jun 18, 2026 1w 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

CVSS Details

Base Score
5.3
Exploitability
1.6
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack Vector Network
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability None

Threat Intelligence

EPSS Exploit Probability
8.8% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor Information Exposure

Affected Products 3

VendorProductVersionRange
mattermostmattermost_server*≥10.11.0  –  <10.11.17
mattermostmattermost_server*≥11.5.0  –  <11.5.5
mattermostmattermost_server*≥11.6.0  –  <11.6.2

References 1

  • mattermost.com https://mattermost.com/security-updates
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.