CVE-2026-80642

A flaw was found in the Linux kernel's liveupdate subsystem. This vulnerability arises from improper reference counting of incoming File-Lifecycle-Bound (FLB) data. A subsystem might hold onto FLB data for an extended period, and without proper reference counting, the FLB structure could be prematurely freed while still in use. This can lead to use-after-free bugs, potentially resulting in memory corruption.

A moderate severity vulnerability was found in the Linux kernel's liveupdate subsystem. When a subsystem obtained incoming File-Lifecycle-Bound (FLB) data via liveupdate_flb_get_incoming(), the returned structure was not reference-counted, so a subsystem that needed to hold onto the FLB data for an extended period during a Live Update, such as during device enumeration, could continue using the data after it had been freed. This could result in a use-after-free, potentially leading to kernel memory corruption or a system crash. Exploitation requires local access to a system that uses the kernel Live Update mechanism; Red Hat scored this flaw CVSS 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), Moderate. The liveupdate FLB code containing this flaw is not present in the kernel packages shipped with any Red Hat Enterprise Linux or Red Hat In-Vehicle OS release tracked by this flaw, so all Red Hat products are marked NOTAFFECTED with the justification that the vulnerable code is not present.

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.