CVE-2026-89660

A flaw was found in the Linux kernel's Network File System Daemon (NFSD). This vulnerability, a use-after-free, occurs during the revocation of client administrative states. A race condition can allow a client's memory to be freed prematurely while still being referenced, potentially leading to system instability or a denial of service. In some scenarios, this type of memory corruption could be exploited by a remote attacker to achieve arbitrary code execution.

This vulnerability is rated as Moderate severity for Red Hat products because successful exploitation depends on winning a tight race condition during NFSv4 client state revocation and only impacts systems actively configured as NFS servers. The kernel NFS server daemon is not enabled by default on standard Red Hat Enterprise Linux installations, significantly limiting exposure on typical deployments. Hosts that do not export file shares over NFSv4 or do not run the nfs-server service are not affected.

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.