CVE-2017-18906: mattermost mattermost_server Improper Authentication
Vulnerability summary
CVE-2017-18906 is a high (CVSS 8.1) Improper Authentication vulnerability in mattermost mattermost_server. EPSS estimates a 0.79% chance of exploitation in the next 30 days, higher than 56.3% of scored vulnerabilities.
Not severe (CVSS 8.1, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 19-06-2020PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
Description
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 metrics
3 scores · 2 sources · 2 versions- OSV · GoEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS trend
Probability
0.79%
Chance of exploitation in the next 30 days
Percentile
56%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.79% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Github.com/mattermost1 product
- mattermost-server< 3.9.2-0.20170714134023-b17fca0d5ee7 | ≥ 3.10.0, < 3.10.2 | ≥ 3.10.0+incompatible, < 3.10.2+incompatible
Mattermost1 product
- mattermost_server< 3.9.2 | ≥ 3.10.0, < 3.10.2
2 vendors · 2 products
