CVE-2026-68451

A flaw was found in the Linux kernel's s390 zcrypt module. The cca_ecc2protkey() function, responsible for handling Common Cryptographic Architecture (CCA) Elliptic Curve Cryptography (ECC) private key requests, does not properly validate the length of the key token. This allows a local attacker to provide a malformed key token, potentially leading to memory corruption and a denial of service.

This vulnerability is rated as Moderate severity because exploitation requires an authenticated local user on IBM Z (s390x) systems with access to cryptographic device nodes, limiting the blast radius. Systems running on other hardware architectures do not use the s390 zcrypt driver and are not affected by this flaw. Even on vulnerable s390x deployments, triggering the issue requires specific CCA coprocessor hardware interactions to process crafted elliptic-curve tokens.

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.