CVE-2026-38991

High severity, CVSS 8.8. EPSS: 0.5% chance of exploitation in the next 30 days.

Cockpit 2.13.5 and earlier is affected by a misconfiguration within the Bucket component _isFileTypeAllowed function where a specially crafted filename bypasses an extension filter. This allows an authenticated attacker to rename arbitrary files with the .php file extension enabling arbitrary code to be executed on the underlying server.

Published 2026-04-29. Last modified 2026-06-17.