CVE-2025-39730

A flaw out of boundary read in the Linux kernel NFS functionality was found in the way connected user sends malicious data to the server. A remote user could use this flaw to crash the system.

A flaw was found in the NFS server implementation where nfs_fh_to_dentry() failed to properly validate the minimal filehandle length before accessing the embedded structure. An attacker with access to an exported NFS share could send a crafted filehandle, leading to out-of-bounds memory access and a potential kernel crash. This issue results in a remote denial of service against the NFS server. This flaw is limited to a missing bounds check in nfs_fh_to_dentry(), which causes an out-of-bounds read and a kernel crash.

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.

To mitigate this issue, prevent module nfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.