CVE-2017-18906

mediumpriority · track · 32EPSS 0.008 · 56 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.79% (56th) EPSS

CVSS 4.9 · medium

Is it mine?

6 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-28

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.

cvss

Technical severity, 0–10. One row per scoring source.

8.1

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.9–8.1

v2.04.9mediumAV:N/AC:M/Au:S/C:P/I:P/A:Nprimary · NVD / NIST USexploitability 6.8 · impact 4.9

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 5.2

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Nsecondary · OSV

v3.17.4highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-287USprimaryCWE-613US

affected products (6)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
mattermost mattermost server< 3.9.2nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server3.10.0 → 3.10.2nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-server< 3.9.2-0.20170714134023-b17fca0d5ee7osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server3.10.0 → 3.10.2osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server3.10.0+incompatible → 3.10.2+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-fpcr-4rr5-hpcpMattermost Server vulnerable to user account takeover when Single Sign-On OAuth2 is used2022-05-24ghsa · osvUS
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.
GO-2026-4477Mattermost Server vulnerable to user account takeover when Single Sign-On OAuth2 is used in github.com/mattermost/mattermost-server2026-02-17vendor · osvUS
Mattermost Server vulnerable to user account takeover when Single Sign-On OAuth2 is used in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/mattermost/mattermost-server before v3.9.2-0.20170714134023-b17fca0d5ee7.

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2020-06-19modified 2026-06-17

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+7722 more

references (4)

External citations — patches, advisories, analysis.

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