Excessive NSEC3 iterations cause high CPU load during insecure delegation validation_CVE-2026-1519

{
    "lastseen": "",
    "description": "If a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU. Authoritative-only servers are generally unaffected, although there are circumstances where authoritative servers may make recursive queries (see: https://kb.isc.org/docs/why-does-my-authoritative-server-make-recursive-queries).\nThis issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.46, 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.46-S1, and 9.20.9-S1 through 9.20.20-S1.",
    "published": "2026-03-25T13:25:19.802Z",
    "modified": "2026-03-25T14:55:40.032Z",
    "type": "cve",
    "title": "Excessive NSEC3 iterations cause high CPU load during insecure delegation validation",
    "source": "isc",
    "references": "https://kb.isc.org/docs/cve-2026-1519\nhttps://downloads.isc.org/isc/bind9/9.18.47\nhttps://downloads.isc.org/isc/bind9/9.20.21\nhttps://downloads.isc.org/isc/bind9/9.21.20",
    "id": "CVE-2026-1519",
    "bulletinFamily": "",
    "cwe": [
        "CWE-606"
    ],
    "cvelist": null,
    "sourceData": "ISC BIND 9 9.11.0\nISC BIND 9 9.18.0\nISC BIND 9 9.20.0\nISC BIND 9 9.21.0\nISC BIND 9 9.11.3-S1\nISC BIND 9 9.18.11-S1\nISC BIND 9 9.20.9-S1",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "BIND 9",
    "version": "9.11.0",
    "vendor": "ISC",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}