CVE-2026-6046

{"id": "CVE-2026-6046", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "responsibledisclosure@mattermost.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 1.6}]}, "published": "2026-06-12T17:16:26.957", "references": [{"url": "https://mattermost.com/security-updates", "source": "responsibledisclosure@mattermost.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "responsibledisclosure@mattermost.com", "description": [{"lang": "en", "value": "CWE-200"}]}], "descriptions": [{"lang": "en", "value": "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"}], "lastModified": "2026-06-12T17:16:26.957", "sourceIdentifier": "responsibledisclosure@mattermost.com"}