CVE-2026-32738

libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 792-byte HEIF sequence file with samples_per_chunk=0 in the stsc box causes an unsigned integer underflow in the Chunk constructor (m_last_sample = 0 + 0 - 1 = UINT32_MAX), mapping all samples to an empty chunk and resulting in a denial of service. When any sample is accessed, the library reads from index 0 of an empty std::vector, causing a guaranteed SEGV (null-page read). The file parses successfully without producing an error; the crash occurs on the first frame access. This issue has been fixed in version 1.22.0.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww	Exploit Vendor Advisory
https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:struktur:libheif:*:*:*:*:*:*:*:*

History

20 May 2026, 14:17

Type	Values Removed	Values Added
CPE		cpe:2.3:a:struktur:libheif::::::::
References	~~() https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww -~~	() https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww - Exploit, Vendor Advisory
First Time		Struktur Struktur libheif

19 May 2026, 20:16

Type	Values Removed	Values Added
References	~~() https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww -~~	() https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww -

19 May 2026, 19:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-19 19:16

Updated : 2026-05-20 14:17

NVD link : CVE-2026-32738

Mitre link : CVE-2026-32738

CVE.ORG link : CVE-2026-32738

JSON object : View

Products Affected

struktur

libheif

CWE

CWE-125

Out-of-bounds Read

CWE-476

NULL Pointer Dereference

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