Research · Aug 19, 2025
Critical Vulnerability Resolved in Linux Kernel's NFS over TLS
A significant vulnerability affecting the Linux kernel's NFS over TLS has been patched, enhancing security for users relying on TLS for data integrity.
What changed
A critical vulnerability identified as CVE-2025-38566 has been addressed in the Linux kernel, specifically related to the handling of server-side TLS alerts in NFS over TLS. The flaw was discovered by Scott Mayhew and stemmed from incorrect assumptions in the kTLS implementation regarding data reading from the message iterator's kvec.
- The patch improves how control messages are set up and utilized by sock_recvmsg() in the kernel.
- This fix prevents potential exploitation of the vulnerability that could lead to unauthorized data access or manipulation.
Who is affected
Organizations and individuals utilizing the Linux kernel for their systems, particularly those implementing NFS over TLS, are at risk from this vulnerability. The impact is significant for various sectors relying on secure data transmission.
- Users of Linux distributions that incorporate the kernel version affected by CVE-2025-38566.
- Organizations leveraging Network File System (NFS) for secure file sharing over TLS.
- Developers and system administrators managing Linux-based cloud environments.
What to do
It is crucial for affected users to update their Linux kernel to the latest version where this vulnerability has been patched. Regular updates help maintain security and prevent exploitation of known vulnerabilities.
- Review and apply the latest kernel updates from your Linux distribution.
- Monitor security advisories for further information on vulnerabilities and patches.
- Implement additional security measures, such as network segmentation and access controls, to mitigate potential risks.