CVE-2026-28231

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.

Weakness classification

• security-advisories@github.com: CWE-125

Primary references

• security-advisories@github.com — Patch
• security-advisories@github.com — Product, Release Notes
• security-advisories@github.com — Exploit, Mitigation, Vendor Advisory