Is CVE-2026-3590 actively exploited?

CVE-2026-3590 has no public evidence of in-the-wild exploitation as of 2026-04-22.

What is the CVSS score for CVE-2026-3590?

CVE-2026-3590 has a CVSS score of 6.5 (MEDIUM severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

How do I patch CVE-2026-3590?

Patch guidance is available from mattermost security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-3590.

CVE-2026-3590 - remediation guidance & executive summary

Q: Which products are affected by CVE-2026-3590?

4 products: mattermost mattermost server, mattermost mattermost server, mattermost mattermost server, mattermost mattermost server.

Description

Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: low
Integrity: low
Availability: none
Weaknesses: CWE-367

Metadata

Primary Vendor: MATTERMOST
Published: 4/15/2026
Last Modified: 4/22/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

mattermost : mattermost_servermattermost : mattermost_servermattermost : mattermost_servermattermost : mattermost_server

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-3590. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-3590

View on NIST NVD

CVE-2026-3590 vulnerability