A NULL pointer dereference in the AppArmor notification handling code of the Ubuntu Linux 6.8 kernel can trigger a kernel panic. The flaw stems from the kernel's SAUCE patch process, which does not defensively handle a null pointer when processing AppArmor events. An attacker who can run code as an unprivileged local user can exploit this weakness, leading to a complete loss of system availability for that host. The flaw is a classic null‑pointer dereference (CWE‑476).

Canonical Ubuntu Linux 6.8 kernel releases that include the SAUCE patches are affected. Any system running this kernel version and its variants is vulnerable.

The CVSS score of 5.5 signals a medium‑impact denial‑of‑service vulnerability with local scope. Because the exploitation requires only local privileges, an unprivileged user can trigger it directly, making it relatively accessible. The EPSS score is not available, and the vulnerability is not listed in CISA KEV, indicating that it has not yet been reported as actively exploited in the wild. Nonetheless, local exploitation can cause a critical outage with no immediate detection unless a crash log is monitored.