libheif has a Heap OOB Read/SEGV Crash via Zero samples_per_chunk_CVE-2026-32738

{
    "lastseen": "",
    "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.",
    "published": "2026-05-19T19:03:48.553Z",
    "modified": "2026-05-19T19:03:48.553Z",
    "type": "cve",
    "title": "libheif has a Heap OOB Read/SEGV Crash via Zero samples_per_chunk",
    "source": "GitHub_M",
    "references": "https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww",
    "id": "CVE-2026-32738",
    "bulletinFamily": "",
    "cwe": [
        "CWE-125",
        "CWE-476"
    ],
    "cvelist": null,
    "sourceData": "strukturag libheif < 1.22.0",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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            "privilegesRequired": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "libheif",
    "version": "< 1.22.0",
    "vendor": "strukturag",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}