Vulnerability in Python Pillow
CVE-2026-59203
Pillow is a Python imaging library. From 12.0.0 through 12.2.0, Pillow's EPS parser in PIL/EpsImagePlugin.py accepts a negative byte count in the %%BeginBinary directive, allowing a crafted EPS file to cause Image.open() to seek backwards to the same directive and parse it repeatedly in an infinite loop. This issue is fixed in version 12.3.0.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (32.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 32.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.004 · change: -0.003
Affected products
- Python Pillow
- Python-Pillow Pillow — versions >= 12.0.0, < 12.3.0
Weakness classification (CWE)
References
- github.com/python-pillow/Pillow/commit/03992618118b4a76b6163cd72ab5ecd684133b83 (Patch)
- github.com/python-pillow/Pillow/pull/9708 (Patch, Issue Tracking)
- github.com/python-pillow/Pillow/releases/tag/12.3.0 (Release Notes)
- github.com/python-pillow/Pillow/security/advisories/GHSA-pg7v-jwj7-p798 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-59203?
- CVE-2026-59203 is a medium-severity vulnerability in Python Pillow, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.3/10. Published 2026-07-14.
- How severe is CVE-2026-59203?
- Medium severity. CVSS v3 base score is 5.3 out of 10.