CVE-2026-89674

A flaw was found in the nfsd component of the Linux kernel. Incorrect calculations in the XDR (External Data Representation) buffer size within the nfsd4_ff_encode_layoutget() function can lead to two critical issues. An attacker could potentially exploit this to write data beyond the intended memory boundaries, which might result in system instability or denial of service. Additionally, this flaw could cause the system to expose sensitive, uninitialized kernel memory to a client, leading to information disclosure.

This vulnerability is rated with an Important severity because unauthenticated or low-privileged remote network clients can trigger heap-based memory corruption or extract uninitialized kernel data, potentially causing a system crash or compromising host confidentiality. However, Red Hat Enterprise Linux releases are not affected by this flaw because the pNFS flexfile layout server functionality is disabled in supported Red Hat kernels. As a result, standard NFS server deployments on Red Hat platforms do not contain or expose the vulnerable encoding routines.

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.