Is CVE-2026-96644 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-96644 being exploited in the wild.

How severe is CVE-2026-96644?

High severity, with a CVSS score of 4, published 21 October 2026.

Which products and versions are affected?

pillow (PyPI) < 13.0.0, ECOSYSTEM:introduced=0,fixed=13.0.0; Python Pillow Pillow prior to 13.0.0 on Windows.

Is there a fix for CVE-2026-96644?

Yes. pillow (PyPI): upgrade to 13.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-96644 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-96644?

Check whether you run pillow (PyPI) or Python Pillow Pillow at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-96644: Pillow heap buffer over-read in WMF image handler on Windows

Q: Which products and versions are affected?

pillow (PyPI) < 13.0.0, ECOSYSTEM:introduced=0,fixed=13.0.0; Python Pillow Pillow prior to 13.0.0 on Windows.

Q: Is there a fix for CVE-2026-96644?

Yes. pillow (PyPI): upgrade to 13.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-96644 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-96644?

Check whether you run pillow (PyPI) or Python Pillow Pillow at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-96644 · Severity: high · CVSS 4 · Published 2026-10-21

Pillow is a Python image processing library used in web applications and data processing workflows. On Windows systems, a specially crafted WMF or EMF image file can trigger a heap buffer over-read in the image renderer, potentially exposing sensitive memory contents or crashing applications that process untrusted image files.

Technologies: pillow (PyPI), Python Pillow Pillow. Vendors: PyPI, Python Pillow.

Quick answers

Is CVE-2026-96644 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-96644 being exploited in the wild.
How severe is CVE-2026-96644?: High severity, with a CVSS score of 4, published 21 October 2026.
Which products and versions are affected?: pillow (PyPI) < 13.0.0, ECOSYSTEM:introduced=0,fixed=13.0.0; Python Pillow Pillow prior to 13.0.0 on Windows.
Is there a fix for CVE-2026-96644?: Yes. pillow (PyPI): upgrade to 13.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-96644 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-96644?: Check whether you run pillow (PyPI) or Python Pillow Pillow at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

pillow (PyPI): upgrade to 13.0.0 or later
```
pip install "pillow>=13.0.0"
```

Technical details

The WmfImagePlugin fails to validate full 32-bit WMF/EMF dimensions before passing them to the native Windows renderer, which truncates to 16-bit values for buffer allocation but uses the original full dimensions for pixel data copying. A crafted wide, short metafile bypasses the decompression-bomb check and causes out-of-bounds heap reads. This affects Windows deployments only and requires processing a malicious image file.

Affected products

Python Pillow Pillow prior to 13.0.0 on Windows

Identifiers

CVE-2026-96644
BIT-PILLOW-2026-96644
GHSA-9v9v-9qvf-h2hj
PYSEC-2026-4343

Timeline

2026-10-21: disclosed
2026-10-04: patched: fix merged to main branch

References

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