CVE-2026-3038 Local DoS and possible privilege escalation via routing sockets
An unprivileged user can crash the FreeBSD kernel via a stack buffer overflow in routing sockets, potentially leading to privilege escalation if mitigations are bypassed.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-3038?
CVE-2026-3038 is a high-severity memory corruption vulnerability in Freebsd Freebsd, published on 9 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The rtsock_msg_buffer() function serializes routing information into a buffer. As a part of this, it copies sockaddr structures into a sockaddr_storage structure on the stack. It assumes that the source sockaddr length field had already been validated, but this is not necessarily the case, and it's possible for a malicious userspace program to craft a request which triggers a 127-byte overflow.
In practice, this overflow immediately overwrites the canary for the rtsock_msg_buffer() stack frame, resulting in a panic once the function returns.
The bug allows an unprivileged user to crash the kernel by triggering a stack buffer overflow in rtsock_msg_buffer(). In particular, the overflow will corrupt a stack canary value that is verified when the function returns; this mitigates the impact of the stack overflow by triggering a kernel panic.
Other kernel bugs may exist which allow userspace to find the canary value and thus defeat the mitigation, at which point local privilege escalation may be possible.
Weakness: CWE-787
Which versions are affected by CVE-2026-3038?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-3038?
No fix has been published for CVE-2026-3038 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-3038 being exploited?
There is no known exploitation of CVE-2026-3038 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-jjxv-p5qr-w2hv.