CVE-2026-74689

A flaw was found in the Linux kernel. An ineffective length check in the vcc_setsockopt() function within the Asynchronous Transfer Mode (ATM) network protocol implementation can lead to a slab-out-of-bounds read. This occurs when a caller passes a mismatched level, bypassing the length check, or when a cgroup Berkeley Packet Filter (BPF) setsockopt filter shrinks the optlen after entry. A local attacker could exploit this to cause a denial of service or potentially disclose sensitive information from kernel memory.

Red Hat rates this vulnerability as a Moderate severity impact because exploitation requires local execution capabilities, restricting the blast radius to a local denial of service or information disclosure rather than remote code execution. Under typical Red Hat Enterprise Linux deployments, Asynchronous Transfer Mode (ATM) network protocols are not utilized, and the associated kernel module is not loaded by default. Consequently, systems are only exposed if local users or containers have permission to create ATM sockets.

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.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.