What’s Vulnerable › Vulnerabilities

CVE-2022-3257: Server-side Denial of Service while processing a specifically crafted GIF file

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-09-23 · updated 2026-06-17
• Weakness: CWE-400

Description

Mattermost version 7.1.x and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded while drafting a post, which allows authenticated users to cause resource exhaustion while processing the file, resulting in server-side Denial of Service.

Affected products

• Mattermost: before 7.2.0 — fixed in 7.2.0

How to fix

Upgrade to a fixed version: Mattermost 7.2.0. Check the vendor advisory for mitigations.

References

• https://hackerone.com/reports/1620170
• https://mattermost.com/security-updates/
• https://hackerone.com/reports/1620170
• https://mattermost.com/security-updates/

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