CVE-2026-52937

A flaw was found in the Linux kernel's tap driver. This vulnerability allows an attacker to potentially disclose sensitive kernel stack memory contents to userspace. The flaw occurs in the tap_ioctl() function when handling the SIOCGIFHWADDR command, where uninitialized portions of a stack-allocated structure are copied to userspace. This information leak could be used to bypass Kernel Address Space Layout Randomization (KASLR), making it easier for attackers to exploit other vulnerabilities.

This vulnerability is classified as Moderate impact because exploitation requires local system access to open a character device interface and results only in an information leak rather than direct code execution or privilege escalation. On standard Red Hat Enterprise Linux systems, macvtap and tap endpoints are predominantly utilized in virtualization workloads where access permissions to device nodes are restricted away from unprivileged accounts. While the leaked uninitialized stack data can be leveraged by a local user with appropriate device permissions to defeat KASLR protections, achieving system compromise requires pairing this issue with a separate kernel vulnerability.

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.