3.5

CVE-2026-4643: mattermost

CVSS: 3.5v3.1LowAnalyzed
Published 18-05-2026Last modified 18-05-2026
Open JSON

Vulnerability summary

CVE-2026-4643 is a low (CVSS 3.5) vulnerability in mattermost. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 20.1% of scored vulnerabilities.

Overall risk
14/100
0100
Low · default modelHow is this calculated?
CVSS score
3.5/10
010
Low · v3.1 (CVE.org)
EPSS score
0.29%
0%100%
Low · +0.12 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-05-2026
    PublishedVulnerability first disclosed.
  2. 18-05-2026
    Last modifiedVulnerability information updated.

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

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.29%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

+0.12 pp

From 0.17% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.29%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mattermost2 products

1 vendor · 2 products

References

1 links