CVE-2017-18906 json
Mattermost Server vulnerable to user account takeover when Single Sign-On OAuth2 is used
published 2020-06-19 6 y ago modified 2026-06-17 4 mo ago also GHSA-fpcr-4rr5-hpcp , GO-2026-4477 , EUVD-2017-9996
- cvss
- 8.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 56%
- public exploits
- 0
- none known
Summary
An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2, when Single Sign-On OAuth2 is used. An attacker could claim somebody else's account.
Patch / fix
- go github.com/mattermost/mattermost-server 3.9.2-0.20170714134023-b17fca0d5ee7, 3.10.2, 3.10.2+incompatible
- mattermost mattermost_server 3.9.2, 3.10.2
- govulncheck-vulndb openSUSE Leap 15.6 0.0.20260226T182644-150000.1.149.1
suse advisories SUSE-SU-2026:0757-1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
Exploit prediction
0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| NVD | 2.0 | 4.9 | AV:N/AC:M/Au:S/C:P/I:P/A:N |
| GitHub | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server | <3.9.2-0.20170714134023-b17fca0d5ee7 >=3.10.0, <3.10.2 >=3.10.0+incompatible, <3.10.2+incompatible |
3.9.2-0.20170714134023-b17fca0d5ee7 3.10.2 3.10.2+incompatible |
Classification
References
-
github.com
/mattermost/mattermost/commit/259ad46f30d0fac2f7c5c14f3b76b2170f7e90c7
web
-
github.com
/mattermost/mattermost/commit/b17fca0d5ee7557e3df1cf1d1da8bd749859e35f
web
-
github.com
/mattermost/mattermost/commit/fbc170733e86f09b46ba754dd03304733d2f482f
web
-
mattermost.com
/security-updates/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2017-18906
advisory
-
github.com
/mattermost/mattermost
package
-
mattermost.com
/security-updates
web
-
github.com
/advisories/GHSA-fpcr-4rr5-hpcp
advisory
Sources
- CVE List CVE-2017-18906
- GitHub Advisory GHSA-fpcr-4rr5-hpcp
- NVD CVE-2017-18906
- OSV GO-2026-4477
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.