What is CVE-2026-59200?

CVE-2026-59200 is a high-severity vulnerability in Python Pillow, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-07-14.

How severe is CVE-2026-59200?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Python Pillow

CVE-2026-59200

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.

Vulnerability class: DoS (Denial of Service)

Published 2026-07-14 · last modified 2026-07-21.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (31.0th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 31.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Python Pillow
Python-Pillow Pillow — versions >= 5.1.0, < 12.3.0

Weakness classification (CWE)

References

github.com/python-pillow/Pillow/security/advisories/GHSA-jjj6-mw9f-p565 (Exploit, Vendor Advisory)
github.com/python-pillow/Pillow/pull/9718 (Patch, Issue Tracking)
github.com/python-pillow/Pillow/commit/f7a31ea75e460e108c37126da1f47812f21f6b09 (Patch)
github.com/python-pillow/Pillow/releases/tag/12.3.0 (Release Notes)

Frequently asked questions

What is CVE-2026-59200?: CVE-2026-59200 is a high-severity vulnerability in Python Pillow, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-07-14.
How severe is CVE-2026-59200?: High severity. CVSS v3 base score is 7.5 out of 10.