CVE-2026-53228

A flaw was found in the Linux kernel's Simple Internet Transition (SIT) tunnel driver for IPv6. When processing network traffic with Generic Segmentation Offload (GSO) enabled, the driver may use a stale pointer to the inner IPv6 header after the socket buffer (skb) head has been reallocated. This can lead to reading from freed memory, potentially allowing an attacker to cause a denial of service or gain access to sensitive information.

This vulnerability is rated with Moderate severity for Red Hat because successful exploitation requires an active IPv6-over-IPv4 (SIT) tunnel interface transmitting Generic Segmentation Offload (GSO) packets, which is not part of standard or default Red Hat Enterprise Linux networking configurations. Under such non-default environments, local users with network transmission rights could trigger a stale memory read during head reallocation, potentially causing a system crash or leaking uninitialized memory. Systems that do not deploy SIT tunnels are not exposed to this issue.

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.