CVE-2026-10819

published 2026-07-27

CVE-2026-10819: Mattermost versions 11.6.x <= 11.6.5, 10.11.x <= 10.11.20, 11.8.x <= 11.8.1, 11.7.x <= 11.7.4 fail to limit the number of frames and enforce the file size cap…

Priority P3 35 medium 6.5 CVSS 3.1

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

Mattermost versions 11.6.x <= 11.6.5, 10.11.x <= 10.11.20, 11.8.x <= 11.8.1, 11.7.x <= 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom emoji.. Mattermost Advisory ID: MMSA-2026-00695

Affected

8 ranges

Vendor	Product	Version range	Fixed in
mattermost	mattermost	10.11.0 – 10.11.20	—
mattermost	mattermost	11.6.0 – 11.6.5	—
mattermost	mattermost	11.7.0 – 11.7.4	—
mattermost	mattermost	11.8.0 – 11.8.1	—
mattermost	mattermost_server	>= 10.11.0 < 10.11.21	10.11.21
mattermost	mattermost_server	>= 11.6.0 < 11.6.6	11.6.6
mattermost	mattermost_server	>= 11.7.0 < 11.7.5	11.7.5
mattermost	mattermost_server	>= 11.8.0 < 11.8.2	11.8.2

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CWE-409