CVE-2026-4643
Calling window.close() from server-side content causes crash in the Mattermost Desktop App
Description
Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost Desktop App which allows a malicious server or plugin to crash the desktop client via invoking {{window.close()}} in the renderer context, leading to a denial of service condition at the client level. Mattermost Advisory ID: MMSA-2026-00633
INFO
Published Date :
May 18, 2026, 9:16 a.m.
Last Modified :
May 18, 2026, 9:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-4643
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | 9302f53e-dde5-4bf3-b2f2-a83f91ac0eee | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Update Mattermost Desktop App to version 6.2 or later.
- Ensure server content is properly validated before rendering.
- Apply vendor patches when available.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-4643.
| URL | Resource |
|---|---|
| https://mattermost.com/security-updates |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-4643 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-4643
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-4643 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-4643 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
May. 18, 2026
Action Type Old Value New Value Added Description Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost Desktop App which allows a malicious server or plugin to crash the desktop client via invoking {{window.close()}} in the renderer context, leading to a denial of service condition at the client level. Mattermost Advisory ID: MMSA-2026-00633 Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L Added CWE CWE-754 Added Reference https://mattermost.com/security-updates