PT-2026-42799 · Mattermost · Mattermost

Eahmed

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Published

2026-05-22

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Updated

2026-05-22

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CVE-2026-28735

CVSS v3.1

5.4

Medium

VectorAV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the OAuth token scope on the callback which allows an authenticated Mattermost user to gain access to private repositories via modifying the scope parameter in the GitHub authorization URL.. Mattermost Advisory ID: MMSA-2026-00628

Fix

Incorrect Authorization

Weakness Enumeration

Related Identifiers

CVE-2026-28735

Affected Products

Mattermost