CVE-2026-100074

A flaw was found in the Linux kernel's extended Berkeley Packet Filter (eBPF) subsystem. The BPF Type Format (BTF) validator failed to enforce that reference count (bpf_refcount) fields are unique within data structures. A local user with permissions to load eBPF programs could exploit this flaw by providing a malformed BTF structure containing multiple reference count fields, leading to a kernel crash and resulting in a Denial of Service (DoS).

This vulnerability is rated as Low severity because successful exploitation requires elevated privileges to load custom eBPF programs, limiting the blast radius on Red Hat Enterprise Linux. By default, unprivileged eBPF execution is disabled across supported Red Hat Enterprise Linux releases, preventing unprivileged local users from injecting malformed BTF data structures. As a result, only authorized users or processes with administrative capabilities such as CAP_BPF or CAP_SYS_ADMIN can interact with the affected subsystem.

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.