CVE-2017-18908: mattermost mattermost_server Improper Authentication
Vulnerability summary
CVE-2017-18908 is a critical (CVSS 9.8) Improper Authentication vulnerability in mattermost mattermost_server. EPSS estimates a 1.18% chance of exploitation in the next 30 days, higher than 67.8% of scored vulnerabilities.
Severe, CVSS 9.8 (NVD); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
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. A password-reset request was sometime sent to an attacker-provided e-mail address.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · GoEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
1.18%
Chance of exploitation in the next 30 days
Percentile
68%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.18% 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, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Github.com/mattermost1 product
- mattermost-server< 3.9.1-rc1 | ≥ 3.10.0, < 3.10.1 | ≥ 3.10.0+incompatible, < 3.10.1+incompatible
Mattermost1 product
- mattermost_server< 3.9.2 | ≥ 3.10.0, < 3.10.2
2 vendors · 2 products
