Mattermost up to 10.5.11/10.11.3 Add Channel Member API Endpoint authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.5$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic was found in Mattermost up to 10.5.11/10.11.3. This issue affects some unknown processing of the component Add Channel Member API Endpoint. Such manipulation leads to authorization. This vulnerability is uniquely identified as CVE-2025-11777. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Mattermost up to 10.5.11/10.11.3 and classified as problematic. Affected by this issue is an unknown function of the component Add Channel Member API Endpoint. 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. CVE summarizes:

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint

The weakness was disclosed by Xiangyu Guo. The advisory is available at mattermost.com. This vulnerability is handled as CVE-2025-11777 since 10/15/2025. The exploitation is known to be difficult. The attack may be launched remotely. The technical details are unknown and an exploit is not available.

Upgrading to version 10.5.12, 10.11.4 or 11.0.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2315). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Mattermost Mattermost

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
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
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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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.5.12/10.11.4/11.0.0

Timelineinfo

10/15/2025 CVE reserved
11/13/2025 +29 days Advisory disclosed
11/13/2025 +0 days VulDB entry created
11/28/2025 +15 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: Xiangyu Guo
Status: Confirmed

CVE: CVE-2025-11777 (🔒)
GCVE (CVE): GCVE-0-2025-11777
GCVE (VulDB): GCVE-100-332402
CERT Bund: WID-SEC-2025-2315 - Mattermost Server und Mobile: Mehrere Schwachstellen

Entryinfo

Created: 11/13/2025 20:24
Updated: 11/28/2025 16:14
Changes: 11/13/2025 20:24 (64), 11/18/2025 06:34 (11), 11/19/2025 02:02 (7), 11/28/2025 16:14 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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