What’s Vulnerable › Vulnerabilities
CVE-2018-21251
- Severity: critical (CVSS 9.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2020-06-19 · updated 2026-06-17
- Weakness: CWE-862
Description
An issue was discovered in Mattermost Server before 5.2 and 5.1.1. Authorization could be bypassed if the channel name were not the same in the params and the body.
Affected products
- Mattermost: before 5.1.1; 5.2.0-rc1, 5.2.0-rc2, 5.2.0-rc3, 5.2.0-rc4, 5.2.0-rc5, 5.2.0-rc6 — fixed in 5.1.1
How to fix
Upgrade to a fixed version: Mattermost 5.1.1. Check the vendor advisory for mitigations.
References
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