CVE-2026-53188

A flaw was found in the Linux kernel's RDMA/core component. This vulnerability arises from insufficient validation of file operations (fops) passed to the ib_get_ucaps() function. A local attacker could exploit this by creating a block device with a device number (dev_t) that aliases a character device (char/block alias), allowing them to masquerade as a legitimate user capabilities (ucap) character device file descriptor. This impersonation could lead to a security bypass, potentially granting unauthorized access to RDMA capabilities.

This vulnerability is rated as having a Moderate impact for Red Hat Enterprise Linux because exploitation is restricted to authenticated local users and requires an existing block device with matching device identifiers to impersonate RDMA user capabilities. Typical Red Hat deployments do not expose RDMA interfaces unless high-performance networking or clustered storage is explicitly configured. While an unprivileged local user could bypass capability checks to access RDMA operations and potentially trigger system instability, the flaw cannot be exploited remotely and does not grant direct administrative privileges.

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.