What is CVE-2026-32738?

CVE-2026-32738 is a medium-severity vulnerability in Struktur Libheif, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-05-19.

How severe is CVE-2026-32738?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Out-of-bounds Read in Struktur Libheif

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_…

Vulnerability class: Buffer Overflow

EPSS: 0.001 (18.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Struktur Libheif
Strukturag Libheif — versions < 1.22.0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read
CWE-476 — NULL Pointer Dereference

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-32738?: CVE-2026-32738 is a medium-severity vulnerability in Struktur Libheif, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-05-19.
How severe is CVE-2026-32738?: Medium severity. CVSS v3 base score is 6.5 out of 10.