CVE-2026-4747

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

3.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-26 07:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:57 UTC Last updatedMost recent change to the record

Details

Published

2026-03-26 07:16 UTC

Last modified

2026-06-17 10:57 UTC

Exploit probability

3.4% · EPSS, next 30 days

Weakness

CWE-121

Record status

Analyzed

Affected

• Freebsd 13.5
• Freebsd 14.3
• Freebsd 14.4
• Freebsd 15.0

Attack profile CVSS 3.1 · 8.8

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High