CVE-2026-55798

Pillow: WindowsViewer.get_command() OS command injection via unescaped shell path

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.

Scores

Weaknesses (CWE)

• CWE-78

Advisories

• GHSA-4x4j-2g7c-83w6 — Pillow: WindowsViewer.get_command() OS command injection via unescaped shell path
• PYSEC-2026-2257 — 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

European references

• ENISA EUVD · EUVD-2026-41898
• GCVE · GCVE-0-2026-55798

CERT-FR advisories

• CERTFR-2026-AVI-1366 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
• CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

• cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* < 12.3.0

Affected products

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-4x4j-2g7c-83w6
• https://github.com/python-pillow/Pillow/commit/8404ea5fe5df40fc34aa1e51403dd6fce0778b8a
• https://github.com/python-pillow/Pillow/commit/88194166691b7b603529b8b036ab3ab9cedd2de4
• https://github.com/python-pillow/Pillow/commit/b0e06caa64c1405aa3da0bb1d2bd9a77ca22de7f
• https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst

Sources