PT-2026-41639 · Mattermost · Mattermost

Lorenzo Gallegos · Published 2026-05-18 · Updated 2026-05-18 · CVE-2026-2325

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.5.0 through 11.5.1 Mattermost versions 10.11.0 through 10.11.13 Mattermost versions 11.4.0 through 11.4.3

Description An authenticated attacker can cause resource exhaustion or denial of service by sending a crafted oversized HTTP POST request to the ' /api/v1/meetings' endpoint. This occurs because the application fails to limit the size of the request body.

Recommendations Update Mattermost versions 11.5.0 through 11.5.1 to a version newer than 11.5.1. Update Mattermost versions 10.11.0 through 10.11.13 to a version newer than 10.11.13. Update Mattermost versions 11.4.0 through 11.4.3 to a version newer than 11.4.3. As a temporary workaround, restrict access to the ' /api/v1/meetings' endpoint to minimize the risk of exploitation.

Fix

DoS

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

CVE-2026-2325

Affected Products

Mattermost

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-2325 · Security Note
• https://mattermost.com/security-updates · Vendor Advisory
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-2325 · Note