CVE-2026-8683 | Mattermost Desktop App versions <=6.1 5.5.13.0 fail to accou… | CVSS 6.5 MEDIUM

Description

Mattermost Desktop App versions <=6.1 5.5.13.0 fail to account for attempting to open extremely long URLs in the Mattermost Desktop App which allows a malicious server owner to crash the application via including a script to call window.open on a very large URL. Mattermost Advisory ID: MMSA-2026-00652

Metadata

CVE ID: CVE-2026-8683
State: PUBLISHED
Assigner: Mattermost
Reserved: 2026-05-15 14:13 UTC
Published: 2026-06-15 14:06 UTC
Last updated: 2026-06-15 16:06 UTC
Primary CWE: CWE-770
CWE-770: Allocation of Resources Without Limits or Throttlin…
Vendor / Product: Mattermost / Mattermost
Sources: cve.org · NVD

Severity & Metrics

6.5 MEDIUM CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
Mattermost	Mattermost	—	0 ≤ 5.5.13, 6.2.0, 5.13.6.0

Weakness (CWE)

CWE	Source	Description
CWE-770	cna	CWE-770: Allocation of Resources Without Limits or Throttling

CVSS scores (1)

Score	Severity	Version	Source	Vector
6.5	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References (1)

MMSA-2026-00652 https://mattermost.com/security-updates