{"vulnerability": "CVE-2026-9816", "sightings": [{"uuid": "ab1097e8-0112-4d32-83cf-358ac7023aa9", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-9816", "type": "seen", "source": "https://bsky.app/profile/cyberhub.blog/post/3mtkmqcmd5q2y", "content": "\ud83d\udccc CVE-2026-9816 - Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to validate BoardMember.Scheme* fields server-side on insert and arch... https://www.cyberhub.blog/cves/CVE-2026-9816", "creation_timestamp": "2026-08-21T01:37:07.508364Z"}, {"uuid": "50bc23bb-95b7-4782-beb6-fca1e5029d66", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-9816", "type": "seen", "source": "https://bsky.app/profile/cyfar.ca/post/3mtemrcuh442e", "content": "~Cybergcca~\nCanadian Cyber Centre issued advisories for vulnerabilities in JetBrains, BeyondTrust, GitLab, and Mattermost products.\n-\nIOCs: CVE-2026-9816\n-\n#PatchNow #ThreatIntel #Vulnerability", "creation_timestamp": "2026-08-18T16:21:42.182308Z"}, {"uuid": "3beeec05-2b27-480f-aa41-c4ef755da984", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-9816", "type": "seen", "source": "https://cyber.gc.ca/en/alerts-advisories/mattermost-security-advisory-av26-828", "content": "", "creation_timestamp": "2026-08-18T16:15:10.522934Z"}, {"uuid": "e94e422b-6903-4dd8-87a2-348286d19fd9", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-9816", "type": "seen", "source": "https://bsky.app/profile/thehackerwire.bsky.social/post/3mtcslyth7u22", "content": "\ud83d\udfe0 CVE-2026-9816 - High (8.3)\n\nMattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to vali...\n\nhttps://www.thehackerwire.com/vulnerability/CVE-2026-9816/\n\n#infosec #cybersecurity #CVE #vulnerability #security #patchstack", "creation_timestamp": "2026-08-17T23:00:47.147722Z"}, {"uuid": "85360efd-a4f9-4a41-a2e4-cc171407f038", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-9816", "type": "seen", "source": "https://bsky.app/profile/cve.skyfleet.blue/post/esnynuv6upzdy", "content": "CVE-2026-9816 - Insufficient server-side validation of board member role fields permits privilege escalation\nCVE ID : CVE-2026-9816\n \n Published : Aug. 17, 2026, 10:17 p.m. | 18\u00a0minutes ago\n \n Description : Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8....", "creation_timestamp": "2026-08-17T23:55:49.925582Z"}]}