Vulnerability Details 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 18.2%
CVSS Severity
CVSS v3 Score 6.5
References
Products affected by CVE-2026-32738
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cpe:2.3:a:struktur:libheif:1.0.0
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cpe:2.3:a:struktur:libheif:1.1.0
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cpe:2.3:a:struktur:libheif:1.10.0
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cpe:2.3:a:struktur:libheif:1.11.0
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cpe:2.3:a:struktur:libheif:1.12.0
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cpe:2.3:a:struktur:libheif:1.13.0
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cpe:2.3:a:struktur:libheif:1.14.0
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cpe:2.3:a:struktur:libheif:1.14.1
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cpe:2.3:a:struktur:libheif:1.14.2
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cpe:2.3:a:struktur:libheif:1.15.0
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cpe:2.3:a:struktur:libheif:1.15.1
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cpe:2.3:a:struktur:libheif:1.15.2
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cpe:2.3:a:struktur:libheif:1.16.0
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cpe:2.3:a:struktur:libheif:1.16.1
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cpe:2.3:a:struktur:libheif:1.16.2
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cpe:2.3:a:struktur:libheif:1.17.0
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cpe:2.3:a:struktur:libheif:1.17.1
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cpe:2.3:a:struktur:libheif:1.17.2
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cpe:2.3:a:struktur:libheif:1.17.3
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cpe:2.3:a:struktur:libheif:1.17.4
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cpe:2.3:a:struktur:libheif:1.17.5
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cpe:2.3:a:struktur:libheif:1.17.6
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cpe:2.3:a:struktur:libheif:1.18.0
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cpe:2.3:a:struktur:libheif:1.18.1
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cpe:2.3:a:struktur:libheif:1.18.2
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cpe:2.3:a:struktur:libheif:1.19.0
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cpe:2.3:a:struktur:libheif:1.19.1
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cpe:2.3:a:struktur:libheif:1.19.2
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cpe:2.3:a:struktur:libheif:1.19.3
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cpe:2.3:a:struktur:libheif:1.19.4
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cpe:2.3:a:struktur:libheif:1.19.5
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cpe:2.3:a:struktur:libheif:1.19.6
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cpe:2.3:a:struktur:libheif:1.19.7
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cpe:2.3:a:struktur:libheif:1.19.8
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cpe:2.3:a:struktur:libheif:1.2.0
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cpe:2.3:a:struktur:libheif:1.20.0
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cpe:2.3:a:struktur:libheif:1.20.1
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cpe:2.3:a:struktur:libheif:1.20.2
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cpe:2.3:a:struktur:libheif:1.21.0
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cpe:2.3:a:struktur:libheif:1.21.1
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cpe:2.3:a:struktur:libheif:1.21.2
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cpe:2.3:a:struktur:libheif:1.3.0
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cpe:2.3:a:struktur:libheif:1.3.1
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cpe:2.3:a:struktur:libheif:1.3.2
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cpe:2.3:a:struktur:libheif:1.4.0
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cpe:2.3:a:struktur:libheif:1.5.0
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cpe:2.3:a:struktur:libheif:1.5.1
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cpe:2.3:a:struktur:libheif:1.6.0
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cpe:2.3:a:struktur:libheif:1.6.1
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cpe:2.3:a:struktur:libheif:1.6.2
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cpe:2.3:a:struktur:libheif:1.8.0
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cpe:2.3:a:struktur:libheif:1.9.0
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cpe:2.3:a:struktur:libheif:1.9.1