CVE-2026-74364

A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) subsystem. Exclusive maps, which are designed to be used by a single program, can be incorrectly inserted as inner maps within a map-in-map structure. This bypasses the intended security checks, allowing an unrelated program to modify the contents of an exclusive map. This vulnerability could enable a malicious actor to rewrite the contents of a frozen map, thereby undermining critical security guarantees.

Red Hat has classified this issue as Moderate impact because exploitation requires local access with elevated privileges, such as CAP_BPF or CAP_SYS_ADMIN, to construct nested eBPF map structures. While an attacker possessing these capabilities could bypass exclusivity checks to mutate frozen maps verified by signed loaders, the requirement for administrative privileges significantly limits the exposure. Additionally, earlier platforms including Red Hat Enterprise Linux 8 and 9 are not affected as 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.