xen — security advisory

{
  "id": "c7f91a82f6d7d43553d3b0d896cdd40600906e92a2777ee933d26534c9610c8f",
  "url": "https://osv.dev/vulnerability/ALPINE-CVE-2026-79609",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ALPINE-CVE-2026-79609",
    "summary": "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.",
    "evidence": "osv:ALPINE-CVE-2026-79609",
    "products": [
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.19.6-r2",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.20.4-r2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.20.4-r2",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.21.2-r2",
            "evidence": "/affected/3/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "ALPINE-CVE-2026-79609",
      "aliases": [
        "ALPINE-CVE-2026-79609"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.19.6-r2"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:apk/alpine/xen?arch=source",
            "ecosystem": "Alpine:v3.21"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-79609.json"
          },
          "ecosystem_specific": {}
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.20.4-r2"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:apk/alpine/xen?arch=source",
            "ecosystem": "Alpine:v3.22"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-79609.json"
          },
          "ecosystem_specific": {}
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.20.4-r2"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:apk/alpine/xen?arch=source",
            "ecosystem": "Alpine:v3.23"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-79609.json"
          },
          "ecosystem_specific": {}
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.21.2-r2"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:apk/alpine/xen?arch=source",
            "ecosystem": "Alpine:v3.24"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-79609.json"
          },
          "ecosystem_specific": {}
        }
      ],
      "modified": "2026-10-23T18:30:02.527636886Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-79609"
      ],
      "references": [
        "https://security.alpinelinux.org/vuln/CVE-2026-79609"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-79609",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 424579,
  "published_at": "2026-10-13T16:17:23.147+00:00"
}