CVE-2026-32739: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in strukturag libheif
libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 800-byte HEIF sequence file causes an infinite loop in Box_stts::get_sample_duration(), consuming 100% CPU indefinitely with zero progress, leading to DoS. The loop has no iteration limit or timeout and is triggered during file open (parsing) - before any user interaction or image decoding. The process stays alive (no crash, no error logged), making it invisible to crash-based monitoring. This issue has been fixed in version 1.22.0.
AI Analysis
Technical Summary
The vulnerability CVE-2026-32739 affects libheif, a HEIF and AVIF file format decoder and encoder. In versions prior to 1.22.0, a specially crafted 800-byte HEIF sequence file causes an infinite loop in the Box_stts::get_sample_duration() method. This loop has no exit condition or iteration limit, resulting in the process consuming 100% CPU indefinitely during file parsing, before any user interaction or image decoding occurs. The process remains alive without crashing or logging errors, which can evade crash-based monitoring systems. The issue is resolved in libheif version 1.22.0.
Potential Impact
An attacker can cause a denial of service by supplying a malicious HEIF file that triggers an infinite loop in libheif versions 1.21.2 and below. This leads to full CPU utilization by the affected process, effectively halting progress without crashing or generating error logs, making it difficult to detect through conventional monitoring.
Mitigation Recommendations
This vulnerability is fixed in libheif version 1.22.0. Users and integrators should upgrade to version 1.22.0 or later to remediate this issue. No other official remediation or temporary fixes are documented. Patch status is confirmed by the vendor advisory indicating the fix in version 1.22.0.
CVE-2026-32739: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') in strukturag libheif
Description
libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 800-byte HEIF sequence file causes an infinite loop in Box_stts::get_sample_duration(), consuming 100% CPU indefinitely with zero progress, leading to DoS. The loop has no iteration limit or timeout and is triggered during file open (parsing) - before any user interaction or image decoding. The process stays alive (no crash, no error logged), making it invisible to crash-based monitoring. This issue has been fixed in version 1.22.0.
CVSS v3.1
Score 6.5medium
Affected software
pkg:github/strukturag/libheifRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-32739 affects libheif, a HEIF and AVIF file format decoder and encoder. In versions prior to 1.22.0, a specially crafted 800-byte HEIF sequence file causes an infinite loop in the Box_stts::get_sample_duration() method. This loop has no exit condition or iteration limit, resulting in the process consuming 100% CPU indefinitely during file parsing, before any user interaction or image decoding occurs. The process remains alive without crashing or logging errors, which can evade crash-based monitoring systems. The issue is resolved in libheif version 1.22.0.
Potential Impact
An attacker can cause a denial of service by supplying a malicious HEIF file that triggers an infinite loop in libheif versions 1.21.2 and below. This leads to full CPU utilization by the affected process, effectively halting progress without crashing or generating error logs, making it difficult to detect through conventional monitoring.
Mitigation Recommendations
This vulnerability is fixed in libheif version 1.22.0. Users and integrators should upgrade to version 1.22.0 or later to remediate this issue. No other official remediation or temporary fixes are documented. Patch status is confirmed by the vendor advisory indicating the fix in version 1.22.0.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-13T15:02:00.628Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a0db4deba1db473627ecdbe
Added to database: 05/20/2026, 13:19:26 UTC
Last enriched: 05/20/2026, 13:35:28 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 74
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