Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate user’s permissions before other validations which allows non-content reviewers to infer a post’s flagged status via direct API call.. Mattermost Advisory ID: MMSA-2026-00754

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00176.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Mattermost Mattermost unaffected
Version Status Constraints
11.10.0 affected ≤ 11.10.0
11.7.0 affected ≤ 11.7.9
11.9.0 affected ≤ 11.9.1
11.8.0 affected ≤ 11.8.5
11.11.0 unaffected —
11.10.1 unaffected —
11.7.10 unaffected —
11.9.2 unaffected —
11.8.6 unaffected —

No data.

No data.

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No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

Update Mattermost to versions 11.11.0, 11.10.1, 11.7.10, 11.9.2, 11.8.6 or higher.

Workaround

No workaround given by the vendor.

References
Link Providers
https://mattermost.com/security-updates cve-icon cve-icon
History

Fri, 16 Oct 2026 07:30:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate user’s permissions before other validations which allows non-content reviewers to infer a post’s flagged status via direct API call.. Mattermost Advisory ID: MMSA-2026-00754
Title Improper order of authorisations in Mattermost GetFile API leads to an authenticated user to determine a post’s quarantined status
Weaknesses CWE-203
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-10-16T14:17:24.943Z

Reserved: 2026-08-01T16:25:43.758Z

Link: CVE-2026-18560

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-16T08:17:12.967

Modified: 2026-10-16T08:17:12.967

Link: CVE-2026-18560

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-16T13:41:42Z

Weaknesses