tarfile extraction filters allow file modification and content disclosure via hard link to symlink

{
  "id": "b2e67f9d486e75d21b5699a41c1677567d402c3f6dac6d346772186e3523c428",
  "url": "https://osv.dev/vulnerability/BIT-libpython-2026-82049",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "tarfile extraction filters allow file modification and content disclosure via hard link to symlink",
    "summary": "In CPython 3.13 and earlier, the tarfile module's data and tar extraction filters are vulnerable to crafted archives containing a hard link to a symbolic link. Such archives may cause extraction to modify the permissions or modification time of a file outside the destination directory, or expose the contents of that file within the extracted tree.",
    "evidence": "osv:BIT-libpython-2026-82049",
    "products": [
      {
        "name": {
          "value": "libpython",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.10.22",
            "evidence": "/affected/0/ranges"
          },
          {
            "value": "3.11.17",
            "evidence": "/affected/0/ranges"
          },
          {
            "value": "3.12.15",
            "evidence": "/affected/0/ranges"
          },
          {
            "value": "3.13.16",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "BIT-libpython-2026-82049",
      "aliases": [
        "BIT-libpython-2026-82049",
        "BIT-python-2026-82049",
        "BIT-python-min-2026-82049",
        "CVE-2026-82049",
        "PSF-0000-CVE-2026-82049",
        "PSF-2026-41"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.10.22"
                },
                {
                  "introduced": "3.11.0"
                },
                {
                  "fixed": "3.11.17"
                },
                {
                  "introduced": "3.12.0"
                },
                {
                  "fixed": "3.12.15"
                },
                {
                  "introduced": "3.13.0"
                },
                {
                  "fixed": "3.13.16"
                }
              ]
            }
          ],
          "package": {
            "name": "libpython",
            "purl": "pkg:bitnami/libpython",
            "ecosystem": "Bitnami"
          },
          "severity": [
            {
              "type": "CVSS_V4",
              "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/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"
            }
          ],
          "database_specific": {
            "source": "https://github.com/bitnami/vulndb/tree/main/data/libpython/BIT-libpython-2026-82049.json"
          }
        }
      ],
      "modified": "2026-10-13T08:15:04.066688928Z",
      "provider": "osv",
      "references": [
        "https://github.com/python/cpython/commit/5a57248b22ad3b9aafcaaadae2c304a1923daeca",
        "https://github.com/python/cpython/commit/b38be2e6cf9d989075ab73412c63e003ebad4ff3",
        "https://github.com/python/cpython/commit/b8f23e307097552eaea2604383a12ab280520d0d",
        "https://github.com/python/cpython/issues/157190",
        "https://github.com/python/cpython/pull/157191",
        "https://mail.python.org/archives/list/security-announce@python.org/thread/EFJWGAZJA56AKSBR2WHMHQZO7RRLZPRH/",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-82049",
        "https://github.com/python/cpython/commit/197663d63afed27f66e10e23c194e8a634e60913",
        "https://github.com/python/cpython/commit/28f315486b3da0352b9a1de1c3c97f4127ba4771",
        "https://github.com/python/cpython/commit/c66df4e70435d257fd488b35ea129c6f317433a8",
        "https://github.com/python/cpython/commit/cc1689830c6b9aaddded2fb9f2fe8116867e2c0e",
        "https://github.com/python/cpython/commit/cccc7ec30212dba2abef53ce4a2bed112ddb690c"
      ],
      "provider_metadata": {
        "cpes": [
          "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*"
        ],
        "severity": "High"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-82049",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 307468,
  "published_at": "2026-09-21T09:00:11.991+00:00"
}