medium4.5
CVE-2026-55798
Pillow: WindowsViewer.get_command() OS command injection via unescaped shell path
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | Pillow | < 12.3.0 | 12.3.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Python | Pillow | before 12.3.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-4x4j-2g7c-83w6
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-4x4j-2g7c-83w6
- https://nvd.nist.gov/vuln/detail/CVE-2026-55798
- 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/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2026-2257.yaml
- https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst