Arbitrary Code Execution Vulnerability in bhyve by FreeBSD
CVE-2026-101311

Currently unrated

Key Information:

Vendor

FreeBSD

Status
FreeBSD
Vendor
CVE Published:
15 October 2026

What is CVE-2026-101311?

A vulnerability exists in the bhyve hypervisor due to the duplication of maximum resolution constants between the framebuffer device model and the RFB modules, resulting in inconsistencies. This flaw allows a malicious guest to manipulate framebuffer BAR writes without proper validation, setting arbitrary width and height values. Furthermore, the lack of synchronization between framebuffer BAR I/O and RFB rendering threads can lead to crashes in the bhyve process or potentially enable the execution of arbitrary code in the host userspace, posing significant security risks.

Affected Version(s)

FreeBSD 15.1-RELEASE

FreeBSD 14.5-RELEASE

FreeBSD 14.4-RELEASE

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:72....
vendor-advisory

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Brian Delgado from Intel using Anthropic Opus 4.8
Joshua Rogers of AISLE Research Team
Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai
.