CVE-2026-74364
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
In the Linux kernel, a vulnerability in the BPF mechanism has been fixed that allowed bypassing the exclusivity guarantee of BPF maps. Exclusive maps (created with excl_prog_hash) could be inserted into outer maps (map-of-maps) and mutated by unrelated programs, bypassing program compatibility checks.
Risk Assessment
The vulnerability could allow an unauthorized BPF program to modify the contents of exclusive maps, potentially leading to data integrity violations or privilege escalation in signed loader environments.
Recommendation
Update the Linux kernel to a patched version and review BPF program configurations for use of exclusive maps.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject exclusive maps as inner maps in map-in-map An exclusive map (created with excl_prog_hash) is bound to a single program by hash: check_map_prog_compatibility() refuses to load any program whose digest does not match map->excl_prog_sha. That check only runs for maps a program references directly, i.e. its used_maps. A map reached at runtime through a map-of-maps is never in used_maps, and bpf_map_meta_equal() does not consider excl_prog_sha, so an exclusive map can be inserted into a non-exclusive outer map and then looked up and mutated by an unrelated program, bypassing the exclusivity guarantee. For the signed loader this defeats the metadata map exclusivity check added in the signed loader: the cached map->sha[] is validated against the signed hash while another program on a hostile host rewrites the frozen map's contents through the outer map.