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

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0018, the 7th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 3 Jul 2026, 08:30 UTC Published by the maintainers as a GitHub repository advisory
2. 31 Oct 2026, 14:11 UTC First seen by agentprime
3. 31 Oct 2026, 14:11 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-4x4j-2g7c-83w6
• OSV: GHSA-4x4j-2g7c-83w6
• github.com/python-pillow/Pillow/security/advisories/GHSA-4x4j-2g7c-83w6
• nvd.nist.gov/vuln/detail/CVE-2026-55798
• github.com/python-pillow/Pillow/commit/8404ea5fe5df40fc34aa1e51403dd6fce0778b8a
• github.com/python-pillow/Pillow/commit/88194166691b7b603529b8b036ab3ab9cedd2de4
• github.com/python-pillow/Pillow/commit/b0e06caa64c1405aa3da0bb1d2bd9a77ca22de7f
• github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2026-2257.yaml
• github.com/python-pillow/Pillow
• github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.