CVE-2026-4858

published 2026-05-21

CVE-2026-4858: 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 check integration URL for path traversal which allows an…

Priority P2 62 critical 9.9 CVSS 3.1

AV N AC L PR L UI N S C C H I H A H

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 check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640

Affected

12 ranges

Vendor	Product	Version range	Fixed in
github.com	mattermost_mattermost-server	>= 10.11.0 < 10.11.15	10.11.15
github.com	mattermost_mattermost-server	>= 11.4.0 < 11.4.5	11.4.5
github.com	mattermost_mattermost-server	>= 11.5.0 < 11.5.4	11.5.4
github.com	mattermost_mattermost-server	>= 11.6.0 < 11.6.1	11.6.1
mattermost	mattermost	10.11.0 – 10.11.14	—
mattermost	mattermost	11.4.0 – 11.4.4	—
mattermost	mattermost	11.5.0 – 11.5.3	—
mattermost	mattermost	11.6.0 – 11.6.0	—
mattermost	mattermost_server	—	—
mattermost	mattermost_server	>= 10.11.0 < 10.11.15	10.11.15
mattermost	mattermost_server	>= 11.4.0 < 11.4.5	11.4.5
mattermost	mattermost_server	>= 11.5.0 < 11.5.4	11.5.4

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CWE-22