CVE-2026-53349

A flaw was found in the Linux kernel's netfilter component, specifically within nf_conntrack. When Network Address Translation (NAT) helpers are unregistered, a pending expectation can retain a pointer to freed module memory. If a connection matching this expectation arrives after the module is unloaded, the system may attempt to execute code from the freed memory, leading to a system crash (Denial of Service). Exploitation of this vulnerability requires specific privileges to unload NAT helper modules.

This vulnerability is rated as having a Moderate impact for Red Hat Enterprise Linux because exploitation requires local administrative privileges (specifically CAP_SYS_MODULE in the initial user namespace) to unload kernel modules during active connection states. Default Red Hat enterprise deployments do not dynamically unload netfilter connection-tracking helpers during operational network traffic. Since unprivileged or remote network actors cannot independently trigger the unregistration sequence that leaves dangling expectation callbacks, the risk is restricted to privileged local denial of service.

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.