Stack-based buffer overflow in FreeBSD - CVE-2026-4747
Published: March 30, 2026
Vulnerability identifier: #VU124681
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-4747
CWE-ID: CWE-121
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code in the kernel or in userspace RPC servers.
The vulnerability exists due to improper input validation in the RPCSEC_GSS packet validation routine when handling RPC packets. A remote attacker can send a specially crafted RPC packet to trigger a stack overflow, leading to arbitrary code execution.
The kernel component kgssapi.ko is vulnerable when loaded, and userspace applications linked with librpcsec_gss that run an RPC server are also vulnerable.
Affected software
FreeBSD
How to mitigate CVE-2026-4747
Install security update from vendor's website.