CVE-2026-91203

A flaw was found in cockpit-files. This vulnerability allows a local attacker to exploit a timing issue, known as a symlink race condition, during privileged file operations such as changing file ownership or permissions. By manipulating directory entries and winning this race, the attacker can redirect these operations to unintended files. This could lead to unauthorized changes in file ownership and permissions on arbitrary files, potentially compromising system integrity and availability by altering system or application states or rendering services unusable.

This Moderate severity flaw in cockpit-files allows a local attacker to arbitrarily modify file ownership or permissions. Exploitation requires a privileged Cockpit user to perform file operations within a directory writable by the attacker, combined with winning a timing race to swap the target file with a symlink. This limits the practical impact to specific, less common operational scenarios.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Until a fixed package is available, avoid performing privileged ownership or permission changes through the Cockpit Files application in directories that are writable by untrusted or low-privileged users. Where possible, restrict or disable superuser-backed file operations (the elevated chown/chmod flows used for file creation, upload, ownership, and permission changes) for shared writable paths, and perform file metadata changes only on trusted directories. Exploitability is substantially reduced when privileged Cockpit sessions do not operate on attacker-writable directories.