CVE-2026-75588NVD

Vulnerability Summary

Mattermost Desktop App versions <=6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme. Mattermost Advisory ID: MMSA-2026-00717

Severity Level

LOW(2.6)

Published Date

Sep 17, 2026

Last Modified

Sep 17, 2026

Exploitation Status

No confirmed exploitation yet

EPSS Score (30-Day)

0.17%Probability

Root Weakness (CWE)

CWE-1287: Unknown/Unlisted Weakness ↗

Refer to the official MITRE database for detailed architectural specifications regarding this weakness.

CVSS v3.1 Base Metrics — Score 2.6 (LOW)

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredLow

User InteractionRequired

ScopeUnchanged

ConfidentialityNone

IntegrityLow

AvailabilityNone

Affected & Patched Versions

Affected Versions

Mattermost Mattermost <= 6.2.2

Patched Versions

Mattermost Mattermost 6.2.2

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