CVE-2026-74364
NVD analysis in progress
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.
What this means
- Exposure
- Exploitable with local access to the machine, with an ordinary user account and with no action from the victim.
- Impact
- An attacker can read sensitive data and modify or destroy data.
- Likelihood
- Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.
What to doFold into the next patch cycle.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.