Mattermost up to 10.5.10/10.11.2 Guest User Permission members authorization

CVSS Meta Temp Score
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CTI Interest Score
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3.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Mattermost up to 10.5.10/10.11.2. It has been classified as problematic. This affects an unknown part of the file /api/v4/channels/{channel_id}/members of the component Guest User Permission Handler. The manipulation leads to authorization. This vulnerability is documented as CVE-2025-10545. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Mattermost up to 10.5.10/10.11.2. This issue affects an unknown code block of the file /api/v4/channels/{channel_id}/members of the component Guest User Permission Handler. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. Impacted is confidentiality. The summary by CVE is:

Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the `/api/v4/channels/{channel_id}/members` endpoint

The weakness was released by lordwillmore. The advisory is shared at mattermost.com. The identification of this vulnerability is CVE-2025-10545 since 09/16/2025. The exploitation is known to be difficult. The attack may be initiated remotely. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 271200 (Mattermost Server 10.5.x < 10.5.11 / 10.11.x < 10.11.3 / 10.12.0 Multiple Vulnerabilities (MMSA-2025-00497, MMSA-2025-00496, MMSA-2025-00516)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 10.5.11, 10.11.3 or 10.12.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (271200). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.5

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 4.3
NVD Vector: 🔒

CNA Base Score: 3.1
CNA Vector (Mattermost): 🔒

CVSSv2info

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

Exploitinginfo

Class: Authorization
CWE: CWE-863 / CWE-285 / 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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Nessus ID: 271200
Nessus Name: Mattermost Server 10.5.x < 10.5.11 / 10.11.x < 10.11.3 / 10.12.0 Multiple Vulnerabilities (MMSA-2025-00497, MMSA-2025-00496, MMSA-2025-00516)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.5.11/10.11.3/10.12.0

Timelineinfo

09/16/2025 CVE reserved
10/16/2025 +30 days Advisory disclosed
10/16/2025 +0 days VulDB entry created
10/23/2025 +7 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: lordwillmore
Status: Confirmed

CVE: CVE-2025-10545 (🔒)
GCVE (CVE): GCVE-0-2025-10545
GCVE (VulDB): GCVE-100-328781

Entryinfo

Created: 10/16/2025 11:12
Updated: 10/23/2025 11:03
Changes: 10/16/2025 11:12 (65), 10/22/2025 06:51 (11), 10/23/2025 11:03 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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