CVE-2026-55798

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

CVSS 4.5 MEDIUMEPSS 0.1%CWE-78

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 4.5EPSS 0.1%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

06 Jul 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

Affected products

python-pillow · Pillow

References

https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst 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/security/advisories/GHSA-4x4j-2g7c-83w6