Medium 6.5Published Oct 21, 2026

CVE-2026-96638Pillow: BMP RLE decoder memory-amplification DoS via unbounded delta escape / absolute mode

Updated under an hour ago (Oct 28, 2026, 12:10 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for python-pillow Pillow

Exploited in the last 30 days

Pillow is a Python imaging library. From 9.1.0 until 13.0.0, BmpRleDecoder.decode() in src/PIL/BmpImagePlugin.py permits crafted RLE BMP delta escapes and absolute-mode runs to append beyond the remaining dest_length without a per-branch cap. A delta can add roughly 255 image rows in one iteration, so a kilobyte-sized file with a large but permitted width can expand the data bytearray to hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.

CVSS: 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400, CWE-770
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 21, 2026

Affected products

Affected products

python-pillow Pillow python_pillow:pillow (from the name)	from 9.1.0, < 13.0.0	CNA record
python pillow python:pillow	from 9.1.0 before 13.0.0	NVD

References

References

https://github.com/python-pillow/Pillow/security/advisories/GHSA-24rc-8hj2-v98c	x-refsource-confirm, vendor-advisory
https://github.com/python-pillow/Pillow/pull/10015	x-refsource-misc, issue-tracking
https://github.com/python-pillow/Pillow/commit/e7794835e323ff2691d9b3a974cade1a44301b9a	x-refsource-misc, patch
https://github.com/python-pillow/Pillow/releases/tag/13.0.0	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.