Penelope unsafe tar extraction allows arbitrary local file write via crafted session archive

{
  "id": "471dd41758e46e5b9ccece16c4d2221da55e86d0f1f87def1ffcf2141d565988",
  "url": "https://osv.dev/vulnerability/CVE-2026-50558",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Penelope unsafe tar extraction allows arbitrary local file write via crafted session archive",
    "summary": "Penelope Shell Handler is a post-exploitation shell handler for authorized security testing. Prior to 0.20.0, the Unix download() implementation in penelope.py used tar.extractall(local_download_folder) on tar archives returned by remote sessions without validating member paths, allowing a malicious or compromised session to write files outside the intended download directory and potentially overwrite ~/.penelope/peneloperc. This issue is fixed in version 0.20.0.",
    "evidence": "osv:CVE-2026-50558",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-50558",
      "aliases": [
        "CVE-2026-50558",
        "GHSA-f42x-p2mx-hm8r",
        "PYSEC-2026-3606"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/brightio/penelope",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "918d312c8e790497b77eb6f2e7a086d00d70a357"
                },
                {
                  "fixed": "a040afb5db32c7e80b5e8a2f9b2164cf911cfa62"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.20.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "a040afb5db32c7e80b5e8a2f9b2164cf911cfa62"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "918d312c8e790497b77eb6f2e7a086d00d70a357"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.20.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.18.0",
            "v0.15.0",
            "v0.14.14",
            "v0.14.8",
            "v0.10.0",
            "v0.9.2",
            "v0.8.5",
            "v0.8.4",
            "v0.8.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50558.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:33.092773650Z",
      "provider": "osv",
      "references": [
        "https://github.com/brightio/penelope/releases/tag/v0.20.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50558.json",
        "https://github.com/brightio/penelope/security/advisories/GHSA-f42x-p2mx-hm8r",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50558",
        "https://github.com/brightio/penelope/commit/a040afb5db32c7e80b5e8a2f9b2164cf911cfa62"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50558.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-50558",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 500231,
  "published_at": "2026-07-29T15:34:05.042+00:00"
}