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VULNERABILITIES

CVE-2026-15754 Details

Description

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

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:4.2 MEDIUMVector:CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://mattermost.com/security-updates [email protected]Vendor Advisory

Weakness Enumeration

CWE-IDCWE NameSource
CWE-863Incorrect Authorization[email protected]

Affected Products

ProductVersions
mattermost mattermost server
>= 11.7.0, < 11.7.7
>= 11.8.0, < 11.8.4

CPE

  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

3 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-15754
NVD Published Date:
Aug 17, 2026
NVD Last Modified:
Aug 18, 2026
Source:
[email protected]
CVE-2026-15754 Details - Not Deferred