A flaw in the X.Org X server’s X Keyboard (Xkb) extension frees a data structure without properly detaching related resources during client cleanup. The resulting use‑after‑free can corrupt memory or cause the X server to crash when a client disconnects, which leads to denial of service. The weakness is classified as CWE‑416.

The vulnerability affects Red Hat Enterprise Linux distributions, including RHEL 6, 7, 8, 9, 10 and the X.Org Xwayland component. Specific version ranges are not listed in the supplied data; however, the referenced Red Hat errata indicate that multiple RHEL releases have mitigations in place. Apart from RHEL, any installation of X.org Xwayland is potentially impacted.

The CVSS score of 7.3 indicates moderate to high severity, while the EPSS score of less than 1% suggests a low current likelihood of exploitation. The flaw is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker requires a client connected to the X server that triggers the cleanup logic; thus the attack vector is most likely local to the host running the X server, or could be remote if the server accepts untrusted network connections. Exploitation would lead to a crash rather than code execution, but repeated crashes could disrupt availability and serve as a foothold for further attacks if the system is otherwise compromised.