jq: Out-of-Bounds Read in jv_parse_sized() Error Formatting for Non-NUL-Terminated Counted Buffers_CVE-2026-39979

{
    "lastseen": "",
    "description": "jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jv_parse_sized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-handling path formats the input buffer using %s in jv_string_fmt(), which reads until a NUL terminator is found rather than respecting the caller-supplied length. This means that when malformed JSON is passed in a non-NUL-terminated buffer, the error construction logic performs an out-of-bounds read past the end of the buffer. The vulnerability is reachable by any libjq consumer calling jv_parse_sized() with untrusted input, and depending on memory layout, can result in memory disclosure or process termination. The issue has been patched in commit 2f09060afab23fe9390cce7cb860b10416e1bf5f.",
    "published": "2026-04-13T22:18:56.252Z",
    "modified": "2026-04-13T22:18:56.252Z",
    "type": "cve",
    "title": "jq: Out-of-Bounds Read in jv_parse_sized() Error Formatting for Non-NUL-Terminated Counted Buffers",
    "source": "GitHub_M",
    "references": "https://github.com/jqlang/jq/security/advisories/GHSA-2hhh-px8h-355p\nhttps://github.com/jqlang/jq/commit/2f09060afab23fe9390cce7cb860b10416e1bf5f",
    "id": "CVE-2026-39979",
    "bulletinFamily": "",
    "cwe": [
        "CWE-125"
    ],
    "cvelist": null,
    "sourceData": "jqlang jq < 2f09060afab23fe9390cce7cb860b10416e1bf5f",
    "sourceHref": "",
    "cvss": {
        "score": 6.9,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
        "baseSeverity": "",
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        "confidentialityImpact": "",
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        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "jq",
    "version": "< 2f09060afab23fe9390cce7cb860b10416e1bf5f",
    "vendor": "jqlang",
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    "ai_score": 0
}