CVE-2026-55798: python-pillow pillow OS Command Injection

Vulnerability summary

CVE-2026-55798 is a medium (CVSS 4.5) OS Command Injection vulnerability in python-pillow pillow. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 6.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 06-07-2026
   PublishedVulnerability first disclosed.
2. 07-07-2026
   Last modifiedVulnerability information updated.

Description

Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=True), allowing shell metacharacters in the file path to inject arbitrary cmd.exe commands. This issue is fixed in version 12.3.0.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.