CVE-2017-18885: mattermost mattermost_server Improper Privilege Management
Vulnerability summary
CVE-2017-18885 is a critical (CVSS 9.8) Improper Privilege Management 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 4.3.0, 4.2.1, and 4.1.2. It allows attackers to gain privileges by accessing unintended API endpoints on a user's behalf.
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 catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not 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< 4.1.2 | ≥ 4.2.0-rc1, < 4.2.1 | ≥ 4.3.0-rc1, < 4.3.0 | ≥ 4.3.0-rc1+incompatible, < 4.3.0+incompatible
Mattermost1 product
- mattermost_server< 4.1.2 | ≥ 4.2.0, < 4.2.1 | 4.3.0:rc1 | 4.3.0:rc2 | 4.3.0:rc3 | 4.3.0:rc4
2 vendors · 2 products