Is CVE-2026-26304 actively exploited?

CVE-2026-26304 has no public evidence of in-the-wild exploitation as of 2026-03-18.

What is the CVSS score for CVE-2026-26304?

CVE-2026-26304 has a CVSS score of 4.3 (MEDIUM severity). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

How do I patch CVE-2026-26304?

Patch guidance is available from mattermost security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-26304.

CVE-2026-26304 - remediation guidance & executive summary

Q: Which products are affected by CVE-2026-26304?

2 products: mattermost mattermost server, mattermost mattermost server.

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2 fail to verify run_create permission for empty playbookId, which allows team members to create unauthorized runs via the playbook run API. Mattermost Advisory ID: MMSA-2025-00542

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack Vector: network
Complexity: low
Privileges: low
User Action: none
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: none
Weaknesses: CWE-863 · Incorrect Authorization

Metadata

Primary Vendor: MATTERMOST
Published: 3/16/2026
Last Modified: 3/18/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

mattermost : mattermost_servermattermost : mattermost_server

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-26304. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-26304

View on NIST NVD

CVE-2026-26304 vulnerability