CVE-2026-9816
- Source
- https://cve.org/CVERecord?id=CVE-2026-9816
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-9816.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-9816
- Downstream
- Published
- 2026-08-17T22:05:24Z
- Modified
- 2026-08-21T03:47:13Z
- Severity
-
- 8.3 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H CVSS Calculator
- Summary
- Insufficient server-side validation of board member role fields permits privilege escalation
- Details
-
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 archive-import paths which allows a board editor or non-guest team member to grant board admin to arbitrary users via POST /api/v2/boards/{boardID}/members and POST /api/v2/teams/{teamID}/archive/import.. Mattermost Advisory ID: MMSA-2026-00685
- Database specific
{ "cna_assigner": "Mattermost", "cwe_ids": [ "CWE-863" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9816.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "11.7.0" }, { "last_affected": "11.7.6" }, { "introduced": "10.11.0" }, { "last_affected": "10.11.21" }, { "introduced": "11.8.0" }, { "last_affected": "11.8.3" } ], "source": "AFFECTED_FIELD" } ] }- References
Affected packages
Git / github.com/mattermost/mattermost
Affected ranges
- Type
- GIT
- Repo
- https://github.com/mattermost/mattermost
- Events
- Database specific
-
Show details
{ "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "10.11.0" }, { "fixed": "10.11.22" }, { "introduced": "11.7.0" }, { "fixed": "11.7.7" }, { "introduced": "11.8.0" }, { "fixed": "11.8.4" } ], "source": "CPE_RANGE" }
Affected versions
@mattermost/client@10.*
@mattermost/client@10.11.0
@mattermost/client@11.*
@mattermost/client@11.7.0
@mattermost/client@11.8.0
@mattermost/shared@11.*
@mattermost/shared@11.7.0
@mattermost/shared@11.8.0
@mattermost/types@10.*
@mattermost/types@10.11.0
@mattermost/types@11.*
@mattermost/types@11.7.0
@mattermost/types@11.8.0
mattermost-redux@10.*
mattermost-redux@10.11.0
mattermost-redux@11.*
mattermost-redux@11.7.0
mattermost-redux@11.8.0
v10.*
v10.11.0
v10.11.0-rc3
v10.11.1
v10.11.1-rc1
v10.11.10
v10.11.11
v10.11.11-rc1
v10.11.11-rc2
v10.11.12
v10.11.13
v10.11.13-rc1
v10.11.14
v10.11.14-rc1
v10.11.15
v10.11.15-rc1
v10.11.16
v10.11.17
v10.11.18
v10.11.19
v10.11.19-rc1
v10.11.2
v10.11.2-rc1
v10.11.2-rc2
v10.11.20
v10.11.21
v10.11.3
v10.11.4
v10.11.4-rc1
v10.11.4-rc2
v10.11.4-rc3
v10.11.5
v10.11.6
v10.11.7
v10.11.8
v10.11.9
v10.11.9-rc1
v11.*
v11.7.0
v11.7.1
v11.7.2
v11.7.3
v11.7.4
v11.7.5
v11.7.5-rc1
v11.7.6
v11.8.0
v11.8.0-rc5
v11.8.1
v11.8.2
v11.8.3