What’s Vulnerable › Vulnerabilities

CVE-2017-18898

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% 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-404

Description

An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5. It allows crafted posts that potentially cause a web browser to hang.

Affected products

• Mattermost: before 4.0.5; from 4.1.0 before 4.1.1; 4.2.0-rc1, 4.2.0-rc2, 4.2.0-rc3, 4.2.0-rc4 — fixed in 4.0.5, 4.1.1

How to fix

Upgrade to a fixed version: Mattermost 4.0.5, 4.1.1. Check the vendor advisory for mitigations.

References

• https://mattermost.com/security-updates/
• https://mattermost.com/security-updates/

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