Junglewise Threat Intelligence

CVE-2026-91147: Red Hat Cockpit denial of service in URL-root handling

CVE-2026-91147 · Severity: medium · CVSS 5.9 · Published 2026-09-18

Vendors: Red Hat.

Executive brief

Red Hat Cockpit is a web-based system management interface for Linux servers. A flaw in its URL-root configuration allows remote attackers without authentication to crash the web service by sending a specially crafted request, causing the management interface to become unavailable. This impacts administrators' ability to manage systems remotely until the service is restarted.

Technical details

The vulnerability is a reachable assertion (CWE-617) in cockpit-ws triggered when WebService.UrlRoot is configured and a request is made to the exact URL-root prefix without a trailing slash. The flaw causes an unhandled exception that terminates the service process. Exploitation requires network access and a non-default configuration; typical deployments with front-end normalization or redirection are less vulnerable.

Affected products

  • Red Hat Cockpit Multiple versions with non-default UrlRoot configuration

Timeline

  • 2026-09-18: disclosed

References

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