CVE-2017-18878 — Incorrect Permission Assignment in Mattermost Mattermost-server

CWE-732 — Incorrect Permission AssignmentCWE-284 — Improper Access ControlCWE-639 — Authorization Bypass Through User-Controlled Key5 documents4 sources
Severity
4.3MEDIUMNVD
EPSS
0.2%
top 53.11%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Github.com Mattermost Mattermost-serverMattermost Server
Timeline
PublishedJun 19
Latest updateDec 15

Description

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. Knowledge of a session ID allows revoking another user's session.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LExploitability: 2.8 | Impact: 1.4

Affected Packages2 packages

▶NVDmattermost/mattermost_server4.2.0 — 4.2.1+2
▶Gogithub.com/mattermost_mattermost-server4.3.0-rc1+incompatible — 4.3.0+incompatible+3

🔴Vulnerability Details

4
OSV
Mattermost Server allows users with a session ID to revoke another users' session in github.com/mattermost/mattermost-server↗2025-12-15
▶
GHSA
Mattermost Server allows users with a session ID to revoke another users' session↗2022-05-24
▶
OSV
Mattermost Server allows users with a session ID to revoke another users' session↗2022-05-24
▶
CVEList
CVE-2017-18878: An issue was discovered in Mattermost Server before 4↗2020-06-19
▶
CVE-2017-18878 — Incorrect Permission Assignment | cvebase