---
id: CVE-2026-110636
title: >-
  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
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 shel…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-78
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T15:17:16.710'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-110636'
references:
  - url: 'https://github.com/revolunet/pypdftk'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/revolunet/pypdftk/blob/1d3b40c3b42fb3cc6b0192d34aba2c21a1efd369/pypdftk.py#L87-L123
    label: disclosure@vulncheck.com
  - url: 'https://github.com/revolunet/pypdftk/issues/56'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/revolunet/pypdftk/pull/57'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/pypdftk-through-0.5-os-command-injection-via-pdf-and-output-paths
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-14T15:36:14.013Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.