CVE-2026-20719: Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which…

PriorityP343high7.5CVSS 3.1

AVNACLPRNUINSUCNINAH

EPSS

0.35%

27.7th percentile

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595

Affected

13 ranges

Vendor	Product	Version range	Fixed in
github.com	mattermost_mattermost_server_v8	>= 10.11.0-rc1 < 10.11.2	10.11.2
github.com	mattermost_mattermost_server_v8	>= 11.2.0-rc1 < 11.2.4	11.2.4
github.com	mattermost_mattermost_server_v8	>= 11.3.0-rc1 < 11.3.2	11.3.2
github.com	mattermost_mattermost_server_v8	>= 11.4.0-rc1 < 11.4.1	11.4.1
github.com	mattermost_mattermost_server_v8	>= 8.0.0-20260105080200-d27a2195068d < 8.0.0-20260217110922-b7d4a1f1f59b	8.0.0-20260217110922-b7d4a1f1f59b
mattermost	mattermost	10.11.0 – 10.11.11	—
mattermost	mattermost	11.2.0 – 11.2.3	—
mattermost	mattermost	11.3.0 – 11.3.1	—
mattermost	mattermost	11.4.0 – 11.4.0	—
mattermost	mattermost_server	>= 10.11.0 < 10.11.12	10.11.12
mattermost	mattermost_server	>= 11.2.0 < 11.2.4	11.2.4
mattermost	mattermost_server	>= 11.3.0 < 11.3.2	11.3.2
mattermost	mattermost_server	>= 11.4.0 < 11.4.1	11.4.1

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