CVE-2026-25780: Memory Exhaustion via Malformed DOC File Upload

Q: What is the severity of CVE-2026-25780?

CVE-2026-25780 is classified as a high-severity vulnerability due to its potential to cause memory exhaustion and denial of service.

Q: How do I fix CVE-2026-25780?

To fix CVE-2026-25780, upgrade Mattermost to version 11.3.1 or later, 11.2.3 or later, or 10.11.11 or later.

Q: Who is affected by CVE-2026-25780?

CVE-2026-25780 affects Mattermost installations running versions 11.3.0, 11.2.2, and 10.11.10.

Q: What kind of attack does CVE-2026-25780 allow?

CVE-2026-25780 allows authenticated attackers to exploit malformed DOC file uploads to exhaust server memory.

Q: Is CVE-2026-25780 a remote or local vulnerability?

CVE-2026-25780 is a local vulnerability that requires authenticated access to exploit.

Published Mar 16, 2026

Updated

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to bound memory allocation when processing DOC files which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted DOC file.. Mattermost Advisory ID: MMSA-2026-00581

Affected Software

4 affected components

Mattermost Mattermost<=11.3.0, <=11.2.2, <=10.11.10

Mattermost Mattermost Server>=10.11.0<10.11.11

Mattermost Mattermost Server>=11.2.0<11.2.3

Mattermost Mattermost Server>=11.3.0<11.3.1

Remediation

Information

Update Mattermost to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher.

Event History

Mar 16, 2026

CVE Published

via MITRE·12:59 PM

Data Sourced

via MITRE·12:59 PM

RemedyDescriptionSeverityWeakness

Data Sourced

via NVD·02:18 PM

DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

What is the severity of CVE-2026-25780?

CVE-2026-25780 is classified as a high-severity vulnerability due to its potential to cause memory exhaustion and denial of service.

How do I fix CVE-2026-25780?