CVE-2026-68453

A flaw was found in the Linux kernel's s390/zcrypt component. This vulnerability arises from insufficient validation of user-controlled length fields within the Common Cryptographic Architecture (CCA) token structures. An attacker could manipulate these fields to cause a buffer over-read or under-run. This could lead to a kernel crash, resulting in a denial of service, or the exposure of sensitive memory information.

This vulnerability is classified with a Moderate severity because exploitation requires authenticated local access to the cryptographic driver interface on IBM Z (s390x) systems, restricting the overall blast radius. While a local user with access to protected key operations can induce an out-of-bounds memory read to trigger an operating system crash or potentially disclose adjacent kernel memory, remote unauthenticated exploitation is not possible. Additionally, Red Hat Enterprise Linux deployments running on non-s390x architectures do not utilize this hardware-specific subsystem and are entirely unaffected.

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.