CVE-2026-11993

EUVD-2026-77361 · Published Sep 14, 2026

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly enforce the limit of concurrent files being processed and handled failed files, which allows a user with permission to upload files to spawn more goroutines than intended and block the indexing of other files via uploading heavy files constantly to the server.. Mattermost Advisory ID: MMSA-2026-00696

Technologies

Mattermost Mattermost Server

Weaknesses

CWE-770

CVSS scores

v3.14.3CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

MITRE ATT&CK

Inferred

Where this vulnerability fits in an attack

ReconImpact

Initial Access Impact

T1190Exploit Public-Facing Application T1498.001Direct Network Flood T1498.002Reflection Amplification T1499Endpoint Denial of Service T1499.001OS Exhaustion Flood T1499.002Service Exhaustion Flood T1499.003Application Exhaustion Flood

References

https://mattermost.com/security-updates

Potentially impacted assets

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