{"id":"CVE-2026-79603","title":"x86 PV guests can free memory pages while still keeping a stale TLB entry\npointing to them","summary":"x86 PV guests can free memory pages while still keeping a stale TLB entry\npointing to them.  A TLB flush is only issued by Xen (if needed) when the\npage is re-used.  Since it's possible for the page to be scrubbed ahead of\nthe TLB flush,…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-664"],"vendor":"Xen","product":"Xen","affected":["Xen"],"published":"2026-09-08","updated":"2026-09-08","sourceUpdated":"2026-09-08T19:20:25.117","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-79603","references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-511.html","label":"security@xen.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/08/8","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://xenbits.xen.org/xsa/advisory-511.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-08T13:42:37.092287Z"},"ingestedAt":"2026-09-08T15:33:26.984Z","epss":0.00231,"epssPercentile":0.14217,"slug":"CVE-2026-79603","body":"## Overview\n\nx86 PV guests can free memory pages while still keeping a stale TLB entry\npointing to them.  A TLB flush is only issued by Xen (if needed) when the\npage is re-used.  Since it's possible for the page to be scrubbed ahead of\nthe TLB flush, there's a window where a PV guest can modify an already\nscrubbed page.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}