Vulnerability Description
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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Struktur | Libheif | < 1.22.0 |
Related Weaknesses (CWE)
References
- https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9wwExploitVendor Advisory
- https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9wwExploitVendor Advisory
FAQ
What is CVE-2026-32738?
CVE-2026-32738 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 unde...
How severe is CVE-2026-32738?
CVE-2026-32738 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-32738?
Check the references section above for vendor advisories and patch information. Affected products include: Struktur Libheif.