Mattermost up to 11.7.9/11.8.5/11.9.1/11.10.0 Permissions permission

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.2$0-$5k2.25-

Summaryinfo

A vulnerability marked as problematic has been reported in Mattermost up to 11.7.9/11.8.5/11.9.1/11.10.0. Affected by this vulnerability is an unknown functionality of the component Permissions. This manipulation causes permission. This vulnerability is handled as CVE-2026-18560. The attack can be initiated remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Mattermost up to 11.7.9/11.8.5/11.9.1/11.10.0. Affected by this vulnerability is an unknown code of the component Permissions. The manipulation with an unknown input leads to a permission vulnerability. The CWE definition for the vulnerability is CWE-275. As an impact it is known to affect confidentiality. The summary by CVE is:

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

The advisory is shared at mattermost.com. This vulnerability is known as CVE-2026-18560 since 08/01/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1222 for this issue.

Upgrading to version 11.7.10, 11.8.6, 11.9.2, 11.10.1 or 11.11.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-102746) and CERT Bund (WID-SEC-2026-4009). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Mattermost Mattermost

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.3
CNA Vector (Mattermost): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Permission
CWE: CWE-275 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 11.7.10/11.8.6/11.9.2/11.10.1/11.11.0

Timelineinfo

08/01/2026 CVE reserved
10/16/2026 +76 days Advisory disclosed
10/16/2026 +0 days VulDB entry created
10/16/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Status: Confirmed

CVE: CVE-2026-18560 (🔒)
GCVE (CVE): GCVE-0-2026-18560
GCVE (VulDB): GCVE-100-421201
EUVD: 🔒
CERT Bund: WID-SEC-2026-4009 - Mattermost: Mehrere Schwachstellen

Entryinfo

Created: 10/16/2026 09:48
Updated: 10/16/2026 14:15
Changes: 10/16/2026 09:48 (63), 10/16/2026 11:00 (1), 10/16/2026 14:15 (7)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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