Quick answers
- Is CVE-2026-96778 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-96778 being exploited in the wild.
- How severe is CVE-2026-96778?
- High severity, with a CVSS score of 4, published 21 October 2026.
- Which products and versions are affected?
- pillow (PyPI) >= 9.4.0, < 13.0.0, ECOSYSTEM:introduced=9.4.0,fixed=13.0.0; Python Pillow Pillow 9.4.0 through 12.x (before 13.0.0).
- Is there a fix for CVE-2026-96778?
- 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-2026-96778 attacked?
- It is attacked over the network or with local access, in a software library.
- Am I affected by CVE-2026-96778?
- 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
A heap overflow exists in ImagingJpegEncode() within src/libImaging/JpegEncode.c when an ICC profile exactly fills the 65536-byte encoder buffer, causing jpeg_write_marker() to write one byte before checking the buffer exhaustion counter, which wraps and allows attacker-controlled data to overwrite adjacent heap memory. The vulnerability requires re-saving an untrusted JPEG with its ICC profile and comment preserved. Exploitation can lead to process crash or code execution depending on heap layout.
Affected products
- Python Pillow Pillow 9.4.0 through 12.x (before 13.0.0)
Identifiers
- CVE-2026-96778
- GHSA-g7cr-3p24-7wf7
Timeline
- 2026-10-21: disclosed
- 2026-10-05: patched: Fix commit merged to main branch