CVE-2026-4643
3.5 · LOWMattermost 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 serve…
Overview
CVE-2026-4643 is a low-severity vulnerability. It was published on May 18, 2026 and has a CVSS 3.1 base score of 3.5 (LOW).
This vulnerability has a CVSS 3.1 base score of 3.5, rated LOW. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical 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
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
References
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Frequently asked questions
What is CVE-2026-4643?
CVE-2026-4643 is a low-severity vulnerability. It was published on May 18, 2026 and has a CVSS 3.1 base score of 3.5 (LOW).
How severe is CVE-2026-4643?
This vulnerability has a CVSS 3.1 base score of 3.5, rated LOW. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-4643?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-4643?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-4643 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.
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