CVE-2025-4128
Mattermost Guest User Information Disclosure Vulnerability
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Mattermost Guest User Information Disclosure Vulnerability
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
- Record
CVE-2025-4128- CVSS 3.1
- 3.1 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2025-18094
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
- Record
EUVD-2025-18094- CVSS 3.1
- 3.1 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-jwhw-xf5v-qgxc
Mattermost allows guest users to view information about public teams they are not members of
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
- Record
GHSA-jwhw-xf5v-qgxc- CVSS 3.1
- 3.1 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
NVD
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
- Record
CVE-2025-4128- CVSS 3.1
- 3.1 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
Mattermost Guest User Information Disclosure Vulnerability
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
- Record
CVE-2025-4128- CVSS 3.1
- 3.1 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVGHSA-jwhw-xf5v-qgxc
Mattermost allows guest users to view information about public teams they are not members of
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
- Record
GHSA-jwhw-xf5v-qgxc- CVSS 3.1
- 3.1 Low
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVGO-2025-3757 No score
Mattermost allows guest users to view information about public teams they are not members of in github.com/mattermost/mattermost-server
Mattermost allows guest users to view information about public teams they are not members of in github.com/mattermost/mattermost-server
- Record
GO-2025-3757- Updated
- 2026-11-02
OSVopenSUSE-SU-2025:15225-1 No score
govulncheck-vulndb-0.0.20250612T141001-1.1 on GA media
These are all security issues fixed in the govulncheck-vulndb-0.0.20250612T141001-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2025:15225-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/mattermost/mattermost/server/v8Go |
before 8.0.0-20250422131222-701ddc896a10 | 8.0.0-20250422131222-701ddc896a10 |
github.com/mattermost/mattermost-serverGo |
10.5.0 up to 10.5.5 | 10.5.5 |
github.com/mattermost/mattermost-serverGo |
9.11.0 up to 9.11.14 | 9.11.14 |
github.com/mattermost/mattermost-serverGo |
9.11.0+incompatible up to 9.11.14+incompatible, 10.5.0+incompatible up to 10.5.5+incompatible | 9.11.14+incompatible10.5.5+incompatible |
github.com/mattermost/mattermost-server/v5Go |
All versions | None known |
github.com/mattermost/mattermost-server/v6Go |
All versions | None known |
govulncheck-vulndbopenSUSE:Tumbleweed From an advisory covering 29 CVEs |
before 0.0.20250612T141001-1.1 | 0.0.20250612T141001-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-4128 is a low vulnerability (CVSS 3.1) in Mattermost, published June 11, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.23%, the 14th percentile. Fixed in github.com/mattermost/mattermost/server/v8 8.0.0-20250422131222-701ddc896a10.
References
mattermost.com/security-updates
nvd.nist.gov/vuln/detail/CVE-2025-4128
github.com/mattermost/mattermost/commit/2138a5f2ca6f75e2b99f6a04ea569d0f680c4fab
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suse.com/security/cve/CVE-2020-36846