SECURELYN

CVE-2026-110636

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.

Scores

9.3
CVSS 9.3 out of 10, critical severity.
2.3%
EPSS 2.3% chance of exploitation in the next 30 days.

The facts

Published
14 October 2026
Last changed
16 October 2026
NVD status
Deferred
Severity
Critical, CVSS 9.3 out of 10 (version 4.0)
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/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…
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
2.3% chance of exploitation activity in the next 30 days (percentile 83).

Is there a Securelyn advisory?

Not yet. Securelyn writes plain-English advisories for the flaws that matter most to businesses. Subscribe to the digest to hear about them.

References