CVE-2026-79611

high

Description

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.

References

https://xenbits.xenproject.org/xsa/advisory-518.html

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-98828

http://xenbits.xen.org/xsa/advisory-518.html

http://www.openwall.com/lists/oss-security/2026/10/13/7

Details

Source: Mitre, NVD

Published: 2026-10-13

Updated: 2026-10-14

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00169