Vulnerability in Python Pillow
CVE-2026-42310
Pillow is a Python imaging library. From version 4.2.0 to before version 12.2.0, an attacker can supply a malicious PDF that causes the process to hang indefinitely, consuming 100% CPU and making the application unresponsive. This issue has been patched in version 12.2.0.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (6.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Python Pillow
- Python-Pillow Pillow — versions >= 4.2.0, < 12.2.0
Weakness classification (CWE)
References
- github.com/python-pillow/Pillow/security/advisories/GHSA-r73j-pqj5-w3x7 (Patch, Vendor Advisory)
- github.com/python-pillow/Pillow/pull/9519 (Patch, Issue Tracking)
- github.com/python-pillow/Pillow/commit/3bf614e4b8615d0ce1d5039efaf6db447fe7c468 (Patch)
- github.com/python-pillow/Pillow/releases/tag/12.2.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-42310?
- CVE-2026-42310 is a medium-severity vulnerability in Python Pillow, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.5/10. Published 2026-05-09.
- How severe is CVE-2026-42310?
- Medium severity. CVSS v3 base score is 5.5 out of 10.