Pillow is a Python imaging library. Prior to 13.0.0 on Windows, src/PIL/WmfImagePlugin.py passes unchecked 32-bit WMF or EMF dimensions to the native drawwmf handler in src/display.c. The handler sizes a DIB allocation from 16-bit-truncated bcWidth and bcHeight fields but copies pixel data using the original full dimensions. A crafted wide, short metafile can pass the pixel-count decompression-bomb check and make the Windows-only renderer read beyond the heap buffer, potentially disclosing memory or crashing the process. This issue is fixed in version 13.0.0.
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History

Wed, 21 Oct 2026 21:00:00 +0000

Type Values Removed Values Added
Description Pillow is a Python imaging library. Prior to 13.0.0 on Windows, src/PIL/WmfImagePlugin.py passes unchecked 32-bit WMF or EMF dimensions to the native drawwmf handler in src/display.c. The handler sizes a DIB allocation from 16-bit-truncated bcWidth and bcHeight fields but copies pixel data using the original full dimensions. A crafted wide, short metafile can pass the pixel-count decompression-bomb check and make the Windows-only renderer read beyond the heap buffer, potentially disclosing memory or crashing the process. This issue is fixed in version 13.0.0.
Title Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)
Weaknesses CWE-125
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-21T20:54:43.537Z

Reserved: 2026-09-23T14:35:50.130Z

Link: CVE-2026-96644

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T21:20:32.943

Modified: 2026-10-21T21:20:32.943

Link: CVE-2026-96644

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses