What’s Vulnerable › Vulnerabilities
CVE-2018-21252
- Severity: medium (CVSS 4.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.6% 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-732
Description
An issue was discovered in Mattermost Server before 5.2, 5.1.1, 5.0.3, and 4.10.3. Attackers could use multiple e-mail addresses to bypass a domain-based policy for signups.
Affected products
- Mattermost: before 4.10.3; from 5.0.0 before 5.0.3; from 5.1.0 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 4.10.3, 5.0.3, 5.1.1
How to fix
Upgrade to a fixed version: Mattermost 4.10.3, 5.0.3, 5.1.1. Check the vendor advisory for mitigations.
References
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