CVE-2026-4643 json
Calling window.close() from server-side content causes crash in the Mattermost Desktop App
published 5mo ago modified 4mo ago also EUVD-2026-30758
- cvss
- 3.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 6%
- public exploits
- 0
- none known
Summary
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
Patch / fix
- Mattermost Mattermost 5.13.5.0, 6.1.1.0, 6.2.0
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-754 Improper Check for Unusual or Exceptional Conditions
References
-
mattermost.com
/security-updates
vendor-advisory
Sources
- CVE List CVE-2026-4643
- NVD CVE-2026-4643
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