An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5, when used as an OAuth 2.0 service provider
Published Jun 19, 2020
8.1
HIGHCVSS 3.1
EPSS 0.83%
Description
An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5, when used as an OAuth 2.0 service provider. Sometimes. resource-owner authorization is bypassed, allowing account takeover.
Affected products
No data.
- < 4.0.5
- ≥ 4.1.0 · < 4.1.1
- 4.2.0
- 4.2.0
- 4.2.0
- 4.2.0
No data.
No Red Hat product state for this CVE.
github.com/mattermost/mattermost-server
Go
Introduced 0 Fixed 4.0.5+incompatiblegithub.com/mattermost/mattermost-server
Go
Introduced 4.1.0+incompatible Fixed 4.1.1+incompatiblegithub.com/mattermost/mattermost-server
Go
Introduced 4.2.0-rc1+incompatible Fixed 4.2.0+incompatible
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | 0 | 4.0.5+incompatible |
| Go | github.com/mattermost/mattermost-server | 4.1.0+incompatible | 4.1.1+incompatible |
| Go | github.com/mattermost/mattermost-server | 4.2.0-rc1+incompatible | 4.2.0+incompatible |
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:S/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Table of values (9 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.83% (0.00828) | 55.94th | v5 (v2026.06.15) |
| Sep 20, 2026 | 0.82% (0.00821) | 55.72th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.07% (0.00065) | 28.82th | v3 (v2023.03.01) |
| Jun 20, 2024 | 0.07% (0.00065) | 28.44th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.07% (0.00065) | 26.41th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.89% (0.00885) | 27.89th | v2 (v2022.01.01) |
| Feb 4, 2022 | 0.89% (0.00885) | 10.50th | v2 (v2022.01.01) |
| Feb 3, 2022 | 0.42% (0.00416) | 10.04th | v5 (v2026.06.15) |
| Apr 14, 2021 | 0.42% (0.00416) | 0.00th | v1 |
References (3)
- https://github.com/advisories/GHSA-gg42-mwr6-p82c Advisory
- https://mattermost.com/security-updates x_refsource_CONFIRMVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2017-18894
| Link | Providers | Tags |
|---|---|---|
| https://github.com/advisories/GHSA-gg42-mwr6-p82c | Advisory | |
| https://mattermost.com/security-updates | x_refsource_CONFIRMVendor Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2017-18894 |
Change history (0)
No recorded changes yet.