---
id: CVE-2025-62821
title: >-
  Microsoft HEIF Image Extensions 1.2.22.0 has an out-of-bounds read because
  CHEIFItemInfoEntry_GetDataSize can return success while leaving the reported
  data size as 0
summary: >-
  Microsoft HEIF Image Extensions 1.2.22.0 has an out-of-bounds read because
  CHEIFItemInfoEntry_GetDataSize can return success while leaving the reported
  data size as 0. This causes a caller to make a 1-byte allocation. Later,
  CopyPixels c…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'
cwe:
  - CWE-125
vendor: microsoft
product: heif_image_extension
affected:
  - heif_image_extension = 1.2.22.0
published: '2026-06-19'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T18:10:00.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-62821'
references:
  - url: 'https://github.com/hyunjungg/CVE-2025-62821'
    label: cve@mitre.org
  - url: 'https://github.com/hyunjungg/CVE-2025-62821'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
epss: 0.01052
epssPercentile: 0.63141
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/hyunjungg/CVE-2025-62821'
  checkedAt: '2026-10-05T18:29:46.180Z'
exploitAvailable: true
ingestedAt: '2026-10-05T18:29:11.169Z'
---

## Overview

Microsoft HEIF Image Extensions 1.2.22.0 has an out-of-bounds read because CHEIFItemInfoEntry_GetDataSize can return success while leaving the reported data size as 0. This causes a caller to make a 1-byte allocation. Later, CopyPixels computes copy_size = stride * abs(roi_height) but does not check the source buffer length before a memmove call.

## Affected

- `heif_image_extension = 1.2.22.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.