Server Performance Issues in Mattermost Product Line
CVE-2026-24458

7.5HIGH

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
16 March 2026

What is CVE-2026-24458?

Certain versions of Mattermost are susceptible to a vulnerability that occurs due to inadequate handling of excessively long passwords. Attackers can exploit this flaw by submitting login attempts with passwords that are several megabytes in size, potentially overwhelming the server's CPU and memory resources. This can lead to significant performance degradation and impact the availability of the Mattermost service.

Affected Version(s)

Mattermost 11.3.0

Mattermost 11.2.0 <= 11.2.2

Mattermost 10.11.0 <= 10.11.10

References

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

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

winfunc
.