What’s Vulnerable › Vulnerabilities
CVE-2019-20844
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% 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-924
Description
An issue was discovered in Mattermost Server before 5.18.0, 5.17.2, 5.16.4, 5.15.4, and 5.9.7. An attacker can spoof a direct-message channel by changing the type of a channel.
Affected products
- Mattermost: before 5.9.7; from 5.15.0 before 5.15.4; from 5.16.0 before 5.16.4; from 5.17.0 before 5.17.2; 5.18.0-rc1, 5.18.0-rc2, 5.18.0-rc3, 5.18.0-rc4 — fixed in 5.15.4, 5.16.4, 5.17.2, 5.9.7
How to fix
Upgrade to a fixed version: Mattermost 5.15.4, 5.16.4, 5.17.2, 5.9.7. Check the vendor advisory for mitigations.
References
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