{"id":"CVE-2026-79609","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-79609","generatedAt":"2026-10-27T23:58:56.844Z","title":"XPTI (Xen Page Table Isolation) was introduced to mitigate Meltdown (CVE-2017-5754, one aspect of XSA-254).","description":"XPTI (Xen Page Table Isolation) was introduced to mitigate Meltdown\n(CVE-2017-5754, one aspect of XSA-254).  This involves copying 64-bit PV\nguest page table entries from guest-chosen root page tables to the Xen-\nchosen one which is in actual use by hardware.  To read the guest root\npage table, the directmap is used.  PV guests, however, have a directmap\nwhich may not cover all memory; in particular this is the case if any\nmemory extends beyond the 5 TiB (CONFIG_BIGMEM=y: 3.5 TiB) address\nboundary.","published":"2026-10-13T16:17:23.000Z","lastModified":"2026-10-20T18:17:22.000Z","status":"Awaiting Analysis","sourceIdentifier":"security@xen.org","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"},"cwe":["CWE-284"],"affected":[],"epss":{"score":0.00106,"percentile":0.01105,"date":"2026-10-26","history":[{"date":"2026-10-14","score":0.00159,"percentile":0.04546}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-20T19:15:07.000Z","detail":{"from":null,"score":"8.8","severity":"HIGH","fromSeverity":null},"summary":"Now scored CVSS 8.8 HIGH."},{"kind":"new","label":"New CVE","at":"2026-10-13T16:17:23.000Z","detail":{"score":null,"severity":null,"publishedAt":"2026-10-13T16:17:23.147Z"},"summary":"New CVE, high severity (CVSS 8.8)."}],"references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-516.html","source":"security@xen.org"},{"url":"http://xenbits.xen.org/xsa/advisory-516.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-79609","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}