CVE-2026-79611
Description
AI Translation Available
For XSA-308 logic was introduced, as VMX VMEntry checks do not like the
exact combination of state which occurs when #DB in intercepted, Single
Stepping is active, and blocked by STI/MovSS is active, despite this being
a legitimate state to be in. The resulting VMEntry failure is fatal to
the guest.
Sadly there is another special sub-case of the above, with branch tracing
enabled. In that case the prior adjustment would still cause a VMentry
failure, as before fatal to the guest.
http://www.openwall.com/lists/oss-security/2026/10/13/7
http://xenbits.xen.org/xsa/advisory-518.html
https://xenbits.xenproject.org/xsa/advisory-518.html