cpio — security advisory

{
  "id": "8e7d8f7fd92524f03a9a044da5febdd50023dca840f3a443a02686cfc0aac689",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-66484",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2026-66484",
    "summary": "GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the link_to_name function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files. This issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad",
    "evidence": "osv:DEBIAN-CVE-2026-66484",
    "products": [
      {
        "name": {
          "value": "cpio",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.13+dfsg-7.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.14+dfsg-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.15+dfsg-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.15+dfsg-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.15+dfsg-2.1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "cpio",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.15+dfsg-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.15+dfsg-2.1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "cpio",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.15+dfsg-2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2.15+dfsg-2.1",
            "evidence": "/affected/2/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2026-66484",
      "aliases": [
        "DEBIAN-CVE-2026-66484"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "cpio",
            "purl": "pkg:deb/debian/cpio?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "versions": [
            "2.13+dfsg-7.1",
            "2.14+dfsg-1",
            "2.15+dfsg-1",
            "2.15+dfsg-2",
            "2.15+dfsg-2.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66484.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "cpio",
            "purl": "pkg:deb/debian/cpio?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "versions": [
            "2.15+dfsg-2",
            "2.15+dfsg-2.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66484.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "cpio",
            "purl": "pkg:deb/debian/cpio?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "versions": [
            "2.15+dfsg-2",
            "2.15+dfsg-2.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-66484.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-25T09:47:38.682647216Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-66484"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2026-66484"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-66484",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 445324,
  "published_at": "2026-08-10T11:17:27.62+00:00"
}