An issue was discovered in Mattermost Server before 5.20.0.
Priority LOW 26CWE-862Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-862.
Summary
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.
Why it matters now
EPSS 0.0092 60th percentileScored 2026-11-07
Fix Fixed github.com/mattermost/mattermost-server/v5 (Go): 5.20.0
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | github.com/mattermost/mattermost-server/v5 (Go) | before 5.20.0 | 5.20.0 | Patch available | GHSA-j2h2-cvwh-cr64 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- github.com/mattermost/mattermost-server/v5 (Go) Vendor— Affected before 5.20.0 Fixed in 5.20.0 Patch available GHSA-j2h2-cvwh-cr64
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | before 5.20.0 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions before 5.20.0 Vulnerable ·Mattermost
Remediation
- Fix · GHSA-j2h2-cvwh-cr64 github.com/mattermost/mattermost-server/v5 (Go) Fixed in 5.20.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2020-14457
- 2026-10-03 Alias added: GHSA-j2h2-cvwh-cr64
References
More Mattermost Server vulnerabilities
- TI-2025-18933 Arbitrary file read in Mattermost Boards via import & export board archive CVSS 3.1CRITICAL 9.9
- TI-2025-04465 Path Traversal Leading to RCE by Any Authenticated Mattermost User CVSS 3.1CRITICAL 9.9
- TI-2017-14068 An issue was discovered in Mattermost Server before 3.6.2. CVSS 3.1CRITICAL 9.8
- TI-2017-14060 An issue was discovered in Mattermost Server before 3.8.2, 3.7.5, and 3.6.7. CVSS 3.1CRITICAL 9.8
- TI-2017-14048 An issue was discovered in Mattermost Server before 4.1.0, 4.0.4, and 3.10.3. CVSS 3.1CRITICAL 9.8
- TI-2025-14360 Arbitrary file read via block duplication in Mattermost Boards CVSS 3.1CRITICAL 9.9
Sources
- CVE-2020-14457 · CVE Program
- CVE-2020-14457 · NVD
- FIRST EPSS
- GHSA-j2h2-cvwh-cr64 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences