CVE-2026-32739 — Denial of Service

title: Free Tier: Infinite Loop in libheif Parsing - CVE-2026-32739
id: scw-2026-05-19-ai-1
status: experimental
level: high
description: |
  Detects processes attempting to parse crafted HEIF or AVIF files using libheif versions prior to 1.22.0. This specific vulnerability (CVE-2026-32739) triggers an infinite loop in Box_stts::get_sample_duration() when processing an 800-byte HEIF sequence, leading to a denial of service by consuming 100% CPU. This rule focuses on the file type and library interaction, as the exploit occurs during file open before user interaction.
author: SCW Feed Engine (AI-generated)
date: 2026-05-19
references:
  - https://shimiscyberworld.com/posts/nvd-CVE-2026-32739/
tags:
  - attack.initial_access
  - attack.t1190
logsource:
    category: process_creation
detection:
  selection:
      Image|endswith:
          - 'libheif.dll'
          - 'libheif.so'
      CommandLine|contains:
          - '.heif'
          - '.avif'
      condition: selection
falsepositives:
  - Legitimate administrative activity

Source: Shimi's Cyber World · License & reuse