CVE-2020-14457
Mattermost Server Sensitive Data Exposure
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
CVE-2020-14457- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
CVE List No score
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
CVE-2020-14457- Updated
- 2026-11-02
EUVDEUVD-2022-4257 No score
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
EUVD-2022-4257- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j2h2-cvwh-cr64
Mattermost Server Sensitive Data Exposure
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
GHSA-j2h2-cvwh-cr64- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
OSV
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
CVE-2020-14457- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-j2h2-cvwh-cr64
Mattermost Server Sensitive Data Exposure
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
GHSA-j2h2-cvwh-cr64- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-862
- Updated
- 2026-11-02
OSVBIT-mattermost-2020-14457 No score
An issue was discovered in Mattermost Server before 5.20.0. Non-members can receive broadcasted team details via the update_team WebSocket event, aka MMSA-2020-0012.
- Record
BIT-mattermost-2020-14457- Updated
- 2026-11-02
OSVGO-2023-1939 No score
Mattermost Server Sensitive Data Exposure in github.com/mattermost/mattermost
Mattermost Server Sensitive Data Exposure in github.com/mattermost/mattermost
- Record
GO-2023-1939- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/mattermost/mattermost-server/v5Go |
before 5.20.0 | 5.20.0 |
mattermostBitnami |
before 5.20.0 | 5.20.0 |
github.com/mattermost/mattermostGo |
All versions | None known |
github.com/mattermost/mattermost-serverGo |
All versions | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-14457 is a medium vulnerability (CVSS 5.3) in Mattermost Server, published June 19, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.92%, the 60th percentile. Fixed in github.com/mattermost/mattermost-server/v5 5.20.0.