CVE-2026-15754

Source
https://cve.org/CVERecord?id=CVE-2026-15754
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-15754.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-15754
Published
2026-08-17T14:36:56Z
Modified
2026-10-28T02:31:00Z
Severity
  • 4.2 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N CVSS Calculator
Summary
Missing per-channel team-scope check in ABAC access control policy unassign allows cross-team policy removal
Details

Mattermost versions 11.7.x <= 11.7.6, 11.8.x <= 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belongs to the requesting admin's team, which allows an authenticated team administrator to remove ABAC (attribute-based access control) policy assignments from channels outside their team via the policy unassign API after a channel has been moved to another team.. Mattermost Advisory ID: MMSA-2026-00718

Database specific
{
    "cna_assigner":  "Mattermost",
    "cwe_ids":  [
        "CWE-863"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15754.json",
    "unresolved_ranges":  [
        {
            "extracted_events":  [
                {
                    "range":  [
                        {
                            "introduced":  "11.7.0"
                        },
                        {
                            "last_affected":  "11.7.6"
                        },
                        {
                            "introduced":  "11.8.0"
                        },
                        {
                            "last_affected":  "11.8.3"
                        }
                    ],
                    "source":  "AFFECTED_FIELD",
                    "strategy":  "StandardRange"
                }
            ]
        }
    ]
}
References

Affected packages

Git / github.com/mattermost/mattermost

Affected ranges

Type
GIT
Repo
https://github.com/mattermost/mattermost
Events
Database specific
Show details
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
            "range":  [
                {
                    "introduced":  "11.7.0"
                },
                {
                    "fixed":  "11.7.7"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "cpe":  "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
            "range":  [
                {
                    "introduced":  "11.8.0"
                },
                {
                    "fixed":  "11.8.4"
                }
            ],
            "source":  "CPE_RANGE"
        }
    ]
}

Affected versions

@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@11.*
@mattermost/types@11.7.0
@mattermost/types@11.8.0
mattermost-redux@11.*
mattermost-redux@11.7.0
mattermost-redux@11.8.0
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

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-15754.json"