TI-2017-14031 Aliases CVE-2017-18883 GHSA-w8cc-3h7q-jhc3

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2, when serving…

MEDIUM 42CWE-331Published 2020-06-19 · Updated 2024-08-05

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · None
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.

Summary

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2, when serving as an OAuth 2.0 Service Provider. There is low entropy for authorization data.

Why it matters now

EPSS 0.01134 66th percentileScored 2026-11-07

Fix Fixed github.com/mattermost/mattermost-server (Go): 4.1.2, 4.2.1, 4.3.0

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 (Go)	before 4.1.2	4.1.2	Patch available	GHSA-w8cc-3h7q-jhc3
—	github.com/mattermost/mattermost-server (Go)	4.2.0-rc1 to before 4.2.1	4.2.1	Patch available	GHSA-w8cc-3h7q-jhc3
—	github.com/mattermost/mattermost-server (Go)	4.3.0-rc1 to before 4.3.0	4.3.0	Patch available	GHSA-w8cc-3h7q-jhc3

— Vendor— Affected all versions Fixed in — No fix listed CNA
github.com/mattermost/mattermost-server (Go) Vendor— Affected before 4.1.2 Fixed in 4.1.2 Patch available GHSA-w8cc-3h7q-jhc3
github.com/mattermost/mattermost-server (Go) Vendor— Affected 4.2.0-rc1 to before 4.2.1 Fixed in 4.2.1 Patch available GHSA-w8cc-3h7q-jhc3
github.com/mattermost/mattermost-server (Go) Vendor— Affected 4.3.0-rc1 to before 4.3.0 Fixed in 4.3.0 Patch available GHSA-w8cc-3h7q-jhc3

CPE configurations NVD · 5

CPE	Versions	Role	Vendor
cpe:2.3:a:mattermost:mattermost_server::::::::	before 4.1.2; 4.2.0 to before 4.2.1	Vulnerable	Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc1::::::	4.3.0 rc1	Vulnerable	Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc2::::::	4.3.0 rc2	Vulnerable	Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc3::::::	4.3.0 rc3	Vulnerable	Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc4::::::	4.3.0 rc4	Vulnerable	Mattermost

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions before 4.1.2; 4.2.0 to before 4.2.1 Vulnerable ·Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc1:*:*:*:*:*:* Versions 4.3.0 rc1 Vulnerable ·Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc2:*:*:*:*:*:* Versions 4.3.0 rc2 Vulnerable ·Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc3:*:*:*:*:*:* Versions 4.3.0 rc3 Vulnerable ·Mattermost
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc4:*:*:*:*:*:* Versions 4.3.0 rc4 Vulnerable ·Mattermost

Remediation

Fix · GHSA-w8cc-3h7q-jhc3 github.com/mattermost/mattermost-server (Go) Fixed in 4.1.2 Advisory →
Fix · GHSA-w8cc-3h7q-jhc3 github.com/mattermost/mattermost-server (Go) Fixed in 4.2.1 Advisory →
Fix · GHSA-w8cc-3h7q-jhc3 github.com/mattermost/mattermost-server (Go) Fixed in 4.3.0 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2017-18883
2026-10-03 Alias added: GHSA-w8cc-3h7q-jhc3

References

Advisory 2

Other 2

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

See all 505 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences