CVE-2017-18885 json
Mattermost Server allows attackers to gain privileges by accessing unintended API endpoints with users' credentials
published 2020-06-19 6 y ago modified 2026-06-17 4 mo ago also GHSA-g78f-6xq7-rrhq , GO-2025-4200 , EUVD-2017-9975
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known
Summary
An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows attackers to gain privileges by accessing unintended API endpoints on a user's behalf.
Patch / fix
- go github.com/mattermost/mattermost-server 4.1.2, 4.1.2+incompatible, 4.2.1, 4.2.1+incompatible, 4.3.0, 4.3.0+incompatible
- mattermost mattermost_server 4.1.2, 4.2.1
- govulncheck-vulndb openSUSE Leap 15.6 0.0.20251230T014957-150000.1.134.1
suse advisories SUSE-SU-2026:0037-1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
Exploit prediction
1.18% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server | <4.1.2 >=4.2.0-rc1, <4.2.1 >=4.3.0-rc1, <4.3.0 <4.1.2+incompatible >=4.2.0-rc1+incompatible, <4.2.1+incompatible >=4.3.0-rc1+incompatible, <4.3.0+incompatible |
4.1.2 4.2.1 4.3.0 4.1.2+incompatible 4.2.1+incompatible 4.3.0+incompatible |
Classification
- Weakness
-
- CWE-269 Improper Privilege Management
References
-
mattermost.com
/security-updates/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2017-18885
advisory
-
github.com
/mattermost/mattermost
package
-
mattermost.com
/security-updates
web
-
github.com
/advisories/GHSA-g78f-6xq7-rrhq
advisory
Sources
- CVE List CVE-2017-18885
- GitHub Advisory GHSA-g78f-6xq7-rrhq
- NVD CVE-2017-18885
- OSV GO-2025-4200
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