CVE-2025-62690: Open redirect in error page when link opened in new tab

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-17 · updated 2026-10-13
Weakness: CWE-601

Description

Mattermost versions 10.11.x <= 10.11.4 fail to validate redirect URLs on the /error page, which allows an attacker to redirect a victim to a malicious site via a crafted link opened in a new tab.

Affected products

Mattermost: from 10.11.0 before 10.11.5 — fixed in 10.11.5

How to fix

Upgrade to a fixed version: Mattermost 10.11.5. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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