Resource exhaustion in Python-Pillow Pillow
CVE-2026-96636
Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Python-Pillow Pillow — versions < 13.0.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-96636?
- CVE-2026-96636 is a medium-severity vulnerability in Python-Pillow Pillow, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-10-21.
- How severe is CVE-2026-96636?
- Medium severity. CVSS v3 base score is 6.5 out of 10.