CVE-2026-3038
The rtsock_msg_buffer() function serializes routing information into a buffer.
Published Mar 9, 2026 · updated Jun 17, 2026 · freebsd freebsd
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.
Code
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No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 9, 2026 · NIST NVD
Detected
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
Jun 17, 2026 · NIST NVD
Updated
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
Affected
- cpe freebsd/freebsd13.5
Sources
- NIST NVDVulnerability recordCVE-2026-3038
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 necessari
nvd.nist.gov