LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk body_CVE-2026-40930

{
    "lastseen": "",
    "description": "LIBPNG is a reference library for use in applications that process PNG (Portable Network Graphics) raster image files. In version 1.8.0, three inter-frame chunk discard paths in the push-mode APNG parser clear the chunk-header flag without consuming the chunk body and CRC, allowing attacker-controlled bytes inside an ignored ancillary chunk to be reinterpreted as a fresh chunk header on the next call to `png_process_data`. Commit faf06924688b62d7c1654b5ceddedbde66ffadb4 fixes the issue.",
    "published": "2026-06-04T14:34:51.843Z",
    "modified": "2026-06-04T15:05:19.991Z",
    "type": "cve",
    "title": "LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk body",
    "source": "GitHub_M",
    "references": "https://github.com/pnggroup/libpng/security/advisories/GHSA-c4v6-gxrq-6g2x\nhttps://github.com/pnggroup/libpng/commit/faf06924688b62d7c1654b5ceddedbde66ffadb4",
    "id": "CVE-2026-40930",
    "bulletinFamily": "",
    "cwe": [
        "CWE-436"
    ],
    "cvelist": null,
    "sourceData": "pnggroup libpng = 1.8.0\npnggroup libpng-apng >= 1.6.49, <= 1.6.57",
    "sourceHref": "",
    "cvss": {
        "score": 5.4,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "libpng",
    "version": "= 1.8.0",
    "vendor": "pnggroup",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}