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VULNERABILITIES

CVE-2026-10103 Details

Description

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing arbitrary post IDs in channels shared with that remote.. Mattermost Advisory ID: MMSA-2026-00689

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:4.3 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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-639Authorization Bypass Through User-Controlled Key[email protected]

Affected Products

ProductVersions
mattermost mattermost server
>= 10.11.0, < 10.11.20
>= 11.6.0, < 11.6.5
>= 11.7.0, < 11.7.3

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-2026-10103
NVD Published Date:
Jul 13, 2026
NVD Last Modified:
Jul 14, 2026
Source:
[email protected]
CVE-2026-10103 Details - Not Deferred