OS Command Injection in Pillow - CVE-2026-55798
Published: July 3, 2026
Vulnerability identifier: #VU136861
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-55798
CWE-ID: CWE-78
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Alex Clark and Contributors
Affected software:
Pillow
Pillow
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary commands.
The vulnerability exists due to command injection in WindowsViewer.get_command() in src/PIL/ImageShow.py when processing a file path in a shell command. A remote attacker can supply a specially crafted file path containing shell metacharacters to execute arbitrary commands.
User interaction is required to open a crafted file path on a Windows system.
How to mitigate CVE-2026-55798
Install security update from vendor's website.