{"id":"CVE-2026-79611","title":"For XSA-308 logic was introduced, as VMX VMEntry checks do not like the\nexact combination of state which occurs when #DB in intercepted, Single\nStepping is active, and blocked by STI/MovSS is active, despite this being\na legitimate state…","summary":"For XSA-308 logic was introduced, as VMX VMEntry checks do not like the\nexact combination of state which occurs when #DB in intercepted, Single\nStepping is active, and blocked by STI/MovSS is active, despite this being\na legitimate state…","severity":"medium","published":"2026-10-13","updated":"2026-10-14","sourceUpdated":"2026-10-14T16:10:14.750","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-79611","references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-518.html","label":"security@xen.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/10/13/7","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://xenbits.xen.org/xsa/advisory-518.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-13T16:35:46.745Z","vendor":"Xen","product":"Xen","affected":["Xen"],"epss":0.00161,"epssPercentile":0.05199,"cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-20T17:31:36.841344Z"},"cvssSource":"adp","slug":"CVE-2026-79611","body":"## Overview\n\nFor XSA-308 logic was introduced, as VMX VMEntry checks do not like the\nexact combination of state which occurs when #DB in intercepted, Single\nStepping is active, and blocked by STI/MovSS is active, despite this being\na legitimate state to be in.  The resulting VMEntry failure is fatal to\nthe guest.\n\nSadly there is another special sub-case of the above, with branch tracing\nenabled.  In that case the prior adjustment would still cause a VMentry\nfailure, as before fatal to the guest.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":226052,"id":"CVE-2026-79611","ts":1792520126400,"field":"cvss","old":null,"new":"5.5"},{"seq":226051,"id":"CVE-2026-79611","ts":1792520126400,"field":"severity","old":"none","new":"medium"}]}