CVE-2026-4643
LowWhat is CVE-2026-4643?
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 Vector Breakdown
CVSS 3.1Exploitable remotely over the network without requiring access to the local system.
No special conditions required. Exploit can be performed reliably and repeatedly.
Basic user account required (e.g. standard login without admin rights).
Victim must take an action (e.g. click a link, open a file) for the exploit to succeed.
Exploiting the vulnerability only affects the vulnerable component itself.
No confidentiality impact. Sensitive data is not exposed.
No integrity impact. Data cannot be modified.
Reduced performance or intermittent outages, but service remains available.
FAQ
CVE-2026-4643 has a CVSS score of 3.5/10, rated as Low. Review the affected products list and apply vendor patches.
CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-4643 scores 3.5/10 (Low). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.
The list of devices confirmed to be affected by CVE-2026-4643 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.
Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.