CVE-2026-10819 — Mattermost Server Denial of Service via Animated GIF Emoji Upload

CVE-2026-10819

Mattermost Server Denial of Service via Animated GIF Emoji Upload PUBLISHED

Description (CNA)

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 (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.6.0 through 11.6.5; affected 10.11.0 through 10.11.20; affected 11.8.0 through 11.8.1; affected 11.7.0 through 11.7.4; unaffected 11.9.0; unaffected 11.6.6; unaffected 10.11.21; unaffected 11.8.2; unaffected 11.7.5

CWE

CWE-409

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.