high8.1
CVE-2026-96644
Pillow: Heap over-read in WMF/EMF rendering via 16-bit dimension truncation (Windows builds)
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | Pillow | < 13.0.0 | 13.0.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Python | Pillow | before 13.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-9v9v-9qvf-h2hj
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-9v9v-9qvf-h2hj
- https://nvd.nist.gov/vuln/detail/CVE-2026-96644
- https://github.com/python-pillow/Pillow/pull/10120
- https://github.com/python-pillow/Pillow/commit/4cf46bee338304c5c8968fd7f132ba0d40c428b7
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0