CVE-2026-43027

A flaw was found in the Linux kernel's netfilter subsystem, specifically within the nf_conntrack_helper. When a connection tracking helper is unregistered, its associated expectations are not properly cleaned up. This oversight can lead to a use-after-free vulnerability, where the system attempts to access memory that has already been released. A local attacker could exploit this to cause a system crash, resulting in a Denial of Service (DoS), or potentially achieve privilege escalation.

Moderate severity is assigned to this flaw because exploitation requires local access and administrative capabilities to dismantle connection tracking helpers, preventing unauthenticated remote attacks. Under typical Red Hat Enterprise Linux deployments, connection tracking helpers remain static and are not dynamically created or removed by unprivileged users during standard operations. While triggering this condition causes a kernel use-after-free that could crash the system or permit local escalation, the prerequisite permissions substantially limit exposure.

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.