Denial of Service Vulnerability in Mattermost by Mattermost
CVE-2026-93850

6.5MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
26 October 2026

What is CVE-2026-93850?

Certain versions of Mattermost are vulnerable to a Denial of Service attack due to improper handling of text extracted from uploaded PDF files. This allows an authenticated user to upload a specially crafted PDF that, when processed, can expand into a large volume of text, ultimately exhausting server memory resources. As a result, legitimate users may experience service interruptions. To ensure security, users should update to the latest versions as recommended in the vendor advisory.

Affected Version(s)

Mattermost 11.9.0 <= 11.9.1

Mattermost 11.8.0 <= 11.8.5

Mattermost 11.7.0 <= 11.7.10

References

https://mattermost.com/security-updates
vendor-advisory

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

alimursaliyev
.