CVE-2026-1046 — Improper Authorization in Handler for Custom URL Scheme in Desktop

CWE-939 — Improper Authorization in Handler for Custom URL Scheme4 documents4 sources

Severity

6.5MEDIUMNVD

CNA7.6

EPSS

0.0%

top 88.45%

CISA KEV

Not in KEV

Exploit

No known exploits

Affected products

Mattermost Desktop Mattermost

Timeline

PublishedFeb 16

Description

Mattermost Desktop App versions <=6.0 6.2.0 5.2.13.0 fail to validate help links which allows a malicious Mattermost server to execute arbitrary executables on a user’s system via the user clicking on certain items in the Help menu Mattermost Advisory ID: MMSA-2026-00577

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NExploitability: 2.8 | Impact: 3.6

Affected Packages2 packages

▶NVDmattermost/mattermost_desktop5.13.2 — 5.13.3+1

▶CVEListV5mattermost/mattermost6.2.0+1

🔴Vulnerability Details

CVEList

Arbitrary application execution via unvalidated server-controlled URLs in Help menu↗2026-02-16

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GHSA

GHSA-gjx5-j34g-5g5p: Mattermost Desktop App versions <=6↗2026-02-16

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🕵️Threat Intelligence

Wiz

CVE-2026-1046 Impact, Exploitability, and Mitigation Steps | Wiz↗

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