CVE-2026-72693 Kbd: local privilege escalation in openvt via incorrect process owner verification allowing passwordless root login

What is CVE-2026-72693?

CVE-2026-72693 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 11 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

`openvt -u` is intended to identify the owner of the current VT and then execute `login` as that user from a privileged context. In the documented `kbrequest`/init usage, the ownership test in `authenticate_user()` relies on `stat("/proc/<pid>/fd/0")`. `stat()` on `/proc/<pid>/fd/0` follows the symlink to the underlying TTY device node. As a result, `buf.st_uid` reflects the owner of the TTY node rather than the owner of the process holding the file descriptor. If the TTY owner returns to `root` or the getty owner after logout while an unprivileged process still has `fd 0` attached to that TTY, the check can incorrectly treat that process as belonging to the privileged console owner. Once that check succeeds, the `-u` path executes a passwordless login as the selected user. In the documented `kbrequest`/init deployment using `openvt -us`, this can result in passwordless `login -f root` on the spawned VT. This report establishes that privilege escalation path for that documented deployment; it does not claim equivalent reachability for deployments that do not use `openvt -u` from a privileged `kbrequest`/init path.

Weakness: CWE-284

Which versions are affected by CVE-2026-72693?

How do I fix CVE-2026-72693?

Apply the vendor's patch.

Is CVE-2026-72693 being exploited?

There is no known exploitation of CVE-2026-72693 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALSA-2026:57597, ALSA-2026:57610, ALSA-2026:78951, AZL-95928, CLSA-2026-1788265535, CLSA-2026-1788600455 and 20 more.