Each RPCSEC_GSS data packet is validated by a routine which checks a signature in the packet. This routine copies a portion of the packet into a stack buffer, but fails to ensure that the buffer is sufficiently large, and a malicious client can trigger a stack overflow. Notably, this does not require the client to authenticate itself first. As kgssapi.ko's RPCSEC_GSS implementation is vulnerable, remote code execution in the kernel is possible by an authenticated user that is able to send packets to the kernel's NFS server while kgssapi.ko is loaded into the kernel. In userspace, applications which have librpcgss_sec loaded and run an RPC server are vulnerable to remote code execution from any client able to send it packets. We are not aware of any such applications in the FreeBSD base system.
History

Thu, 26 Mar 2026 07:00:00 +0000

Type Values Removed Values Added
Description Each RPCSEC_GSS data packet is validated by a routine which checks a signature in the packet. This routine copies a portion of the packet into a stack buffer, but fails to ensure that the buffer is sufficiently large, and a malicious client can trigger a stack overflow. Notably, this does not require the client to authenticate itself first. As kgssapi.ko's RPCSEC_GSS implementation is vulnerable, remote code execution in the kernel is possible by an authenticated user that is able to send packets to the kernel's NFS server while kgssapi.ko is loaded into the kernel. In userspace, applications which have librpcgss_sec loaded and run an RPC server are vulnerable to remote code execution from any client able to send it packets. We are not aware of any such applications in the FreeBSD base system.
Title Remote code execution via RPCSEC_GSS packet validation
Weaknesses CWE-121
References

cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-03-26T06:21:12.735Z

Reserved: 2026-03-24T03:57:38.500Z

Link: CVE-2026-4747

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-26T07:16:20.670

Modified: 2026-03-26T07:16:20.670

Link: CVE-2026-4747

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.