pypdftk through 0.5 OS Command Injection via PDF and Output Paths

{
  "id": "8e3779ba38d536e5df3226ecd6a7e8c42a4631934d68ae7ecff811dcab68e198",
  "url": "https://osv.dev/vulnerability/CVE-2026-110636",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "pypdftk through 0.5 OS Command Injection via PDF and Output Paths",
    "summary": "pypdftk through 0.5 contains an OS command injection vulnerability in fill_form(), dump_data_fields(), and pdftk_cmd_util() that builds shell commands from caller-supplied paths. Attackers controlling pdf_path or out_file can inject shell metacharacters interpreted by subprocess.Popen with shell=True to execute OS commands as the Python process.",
    "evidence": "osv:CVE-2026-110636",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-110636",
      "aliases": [
        "CVE-2026-110636"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/revolunet/pypdftk",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "1d3b40c3b42fb3cc6b0192d34aba2c21a1efd369"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.5"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.5"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.5",
            "v0.4",
            "v0.3",
            "v0.2",
            "pypdftk-0.2"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-110636.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.162240018Z",
      "provider": "osv",
      "references": [
        "https://pypi.org",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110636.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-110636",
        "https://www.vulncheck.com/advisories/pypdftk-through-0.5-os-command-injection-via-pdf-and-output-paths",
        "https://github.com/revolunet/pypdftk/issues/56",
        "https://github.com/revolunet/pypdftk/pull/57",
        "https://github.com/revolunet/pypdftk",
        "https://github.com/revolunet/pypdftk/blob/1d3b40c3b42fb3cc6b0192d34aba2c21a1efd369/pypdftk.py#L87-L123"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-78"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110636.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-110636",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 497251,
  "published_at": "2026-10-14T14:17:08.465+00:00"
}