CVE-2026-89542

A flaw was found in the Linux kernel's SUNRPC (Sun Remote Procedure Call) implementation. This vulnerability, located in the gss_krb5_unwrap_v2 function, arises when the system processes specially crafted short tokens or tokens with an invalid length. An attacker could exploit this by providing such a token, leading to memory corruption. This could result in a denial of service (DoS), making the system unavailable.

This vulnerability is rated as having Moderate impact for Red Hat Enterprise Linux and OpenShift environments because exploitation requires an established Kerberos-authenticated RPC session, limiting the attack surface to configurations actively using RPCSEC_GSS. In typical deployments, standard unauthenticated or system-authenticated NFS shares do not invoke this Kerberos token processing path, restricting exposure to systems explicitly participating in Kerberos realms. While an authenticated endpoint submitting malformed or truncated tokens can cause an out-of-bounds memory read or kernel panic, it cannot compromise hosts that do not negotiate Kerberos security flavors.

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.