CVE-2026-28735

—

CVSS 3.1

5.4 medium

EPSS

<1%p4

Published

May 22, 2026 (May 22, 2026)

Modified

Jul 23, 2026

Description

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

Vendors: mattermost
Products: mattermost server
Weakness: CWE-863
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

NVD CVE.org GitHub PoCs EPSS (0.1%)

In the news0 stories

No ingested article mentions this CVE yet.