{"id":"DEBIAN-CVE-2026-79609","details":"XPTI (Xen Page Table Isolation) was introduced to mitigate Meltdown (CVE-2017-5754, one aspect of XSA-254).  This involves copying 64-bit PV guest page table entries from guest-chosen root page tables to the Xen- chosen one which is in actual use by hardware.  To read the guest root page table, the directmap is used.  PV guests, however, have a directmap which may not cover all memory; in particular this is the case if any memory extends beyond the 5 TiB (CONFIG_BIGMEM=y: 3.5 TiB) address boundary.","modified":"2026-10-14T06:00:19.583854669Z","published":"2026-10-13T16:17:23.147Z","upstream":["CVE-2026-79609"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-79609"}],"affected":[{"package":{"name":"xen","ecosystem":"Debian:12","purl":"pkg:deb/debian/xen?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.17.1+2-gb773c48e36-1","4.17.2+55-g0b56bed864-1","4.17.2+76-ge1f9cb16e2-1","4.17.2+76-ge1f9cb16e2-1~deb12u1","4.17.2-1","4.17.3+10-g091466ba55-1","4.17.3+10-g091466ba55-1.1","4.17.3+10-g091466ba55-1.1~exp1","4.17.3+10-g091466ba55-1.1~exp2","4.17.3+10-g091466ba55-1~deb12u1","4.17.3+36-g54dacb5c02-1","4.17.5+23-ga4e5191dc0-1","4.17.5+23-ga4e5191dc0-1+deb12u1","4.17.5+72-g01140da4e8-1","4.17.7-0+deb12u1","4.19.0+14-g0918434e0f-1~exp1","4.19.1-1","4.19.1-1~exp1","4.19.1-1~exp4","4.20.0+68-g35cb38b222-1","4.20.0-1","4.20.0~rc2+1-gfcde5e0de8-1~exp1","4.20.2+37-g61ff35323e-1","4.20.2+7-g1badcf5035-1","4.20.2+7-g1badcf5035-2","4.20.3+127-gc42374a105-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-79609.json"}},{"package":{"name":"xen","ecosystem":"Debian:13","purl":"pkg:deb/debian/xen?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.20.0+68-g35cb38b222-1","4.20.2+37-g61ff35323e-0+deb13u1","4.20.2+37-g61ff35323e-1","4.20.2+7-g1badcf5035-0+deb13u1","4.20.2+7-g1badcf5035-1","4.20.2+7-g1badcf5035-2","4.20.3+127-gc42374a105-0+deb13u1","4.20.3+127-gc42374a105-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-79609.json"}},{"package":{"name":"xen","ecosystem":"Debian:14","purl":"pkg:deb/debian/xen?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.20.0+68-g35cb38b222-1","4.20.2+37-g61ff35323e-1","4.20.2+7-g1badcf5035-1","4.20.2+7-g1badcf5035-2","4.20.3+127-gc42374a105-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-79609.json"}}],"schema_version":"1.9.0"}