Vulnerability Description
pillow_heif is a Python library for working with HEIF images and plugin for Pillow. Prior to version 1.3.0, an integer overflow in the encode path buffer validation of `_pillow_heif.c` allows an attacker to bypass bounds checks by providing large image dimensions, resulting in a heap out-of-bounds read. This can lead to information disclosure (server heap memory leaking into encoded images) or denial of service (process crash). No special configuration is required — this triggers under default settings. Version 1.3.0 fixes the issue.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Bigcat88 | Pillow-Heif | < 1.3.0 |
Related Weaknesses (CWE)
References
- https://github.com/bigcat88/pillow_heif/commit/8305a15d3780c533b762578cbe987d27aPatch
- https://github.com/bigcat88/pillow_heif/releases/tag/v1.3.0ProductRelease Notes
- https://github.com/bigcat88/pillow_heif/security/advisories/GHSA-5gjj-6r7v-ph3xExploitMitigationVendor Advisory
FAQ
What is CVE-2026-28231?
CVE-2026-28231 is a vulnerability with a CVSS score of 9.1 (CRITICAL). pillow_heif is a Python library for working with HEIF images and plugin for Pillow. Prior to version 1.3.0, an integer overflow in the encode path buffer validation of `_pillow_heif.c` allows an attac...
How severe is CVE-2026-28231?
CVE-2026-28231 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-28231?
Check the references section above for vendor advisories and patch information. Affected products include: Bigcat88 Pillow-Heif.