id: PYSEC-2026-2248
published: "2026-02-27T20:21:40.697Z"
modified: "2026-07-13T05:50:42.860215Z"
aliases:
- CVE-2026-28231
- GHSA-5gjj-6r7v-ph3x
details: 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.
affected:
- package:
    name: pi-heif
    ecosystem: PyPI
    purl: pkg:pypi/pi-heif
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 1.3.0
  versions:
  - 0.10.0
  - 0.10.1
  - 0.11.0
  - 0.11.1
  - 0.12.0
  - 0.13.0
  - 0.13.1
  - 0.14.0
  - 0.15.0
  - 0.16.0
  - 0.17.0
  - 0.18.0
  - 0.20.0
  - 0.21.0
  - 0.22.0
  - 0.7.0
  - 0.7.1
  - 0.7.2
  - 0.8.0
  - 0.9.0
  - 0.9.1
  - 0.9.2
  - 0.9.3
  - 1.0.0
  - 1.1.0
  - 1.1.1
  - 1.2.0
  - 1.2.1
  ecosystem_specific: {}
references:
- type: ADVISORY
  url: https://github.com/bigcat88/pillow_heif/releases/tag/v1.3.0
- type: FIX
  url: https://github.com/bigcat88/pillow_heif/commit/8305a15d3780c533b762578cbe987d27a2c59c7a
- type: EVIDENCE
  url: https://github.com/bigcat88/pillow_heif/security/advisories/GHSA-5gjj-6r7v-ph3x
severity:
- type: CVSS_V3
  score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H