Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash_CVE-2026-21909

{
    "lastseen": "",
    "description": "A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a specific update packet causing a memory leak.\u00a0Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition.\n\nMemory usage can be monitored through the use of the 'show task memory detail' command. For example:\n\nuser@junos> show task memory detail | match ted-infra\n\u00a0 TED-INFRA-COOKIE  \u00a0 \u00a0 \u00a0 \u00a0 \u00a0  25  \u00a0  1072  \u00a0 \u00a0  28  \u00a0  1184  \u00a0 \u00a0  229\n\n\n\nuser@junos> \n\nshow task memory detail | match ted-infra\n\u00a0 TED-INFRA-COOKIE  \u00a0 \u00a0 \u00a0 \u00a0 \u00a0  31  \u00a0  1360  \u00a0 \u00a0  34  \u00a0  1472  \u00a0 \u00a0  307\n\nThis issue affects:\n\nJunos OS:\u00a0\n\n  *  from 23.2 before 23.2R2,\u00a0\n  *  from 23.4 before 23.4R1-S2, 23.4R2,\u00a0\n  *  from 24.1 before 24.1R2;\u00a0\n\n\nJunos OS Evolved:\u00a0\n\n  *  from 23.2 before 23.2R2-EVO,\u00a0\n  *  from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,\u00a0\n  *  from 24.1 before 24.1R2-EVO.\n\n\nThis issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.",
    "published": "2026-01-15T20:22:44.674Z",
    "modified": "2026-01-15T20:52:42.400Z",
    "type": "cve",
    "title": "Junos OS and Junos OS Evolved: Receipt of specific IS-IS update packet causes memory leak leading to RPD crash",
    "source": "juniper",
    "references": "https://supportportal.juniper.net/JSA106008\nhttps://kb.juniper.net/JSA106008",
    "id": "CVE-2026-21909",
    "bulletinFamily": "",
    "cwe": [
        "CWE-401"
    ],
    "cvelist": null,
    "sourceData": "Juniper Networks Junos OS 23.2\nJuniper Networks Junos OS 23.4\nJuniper Networks Junos OS 24.1\nJuniper Networks Junos OS Evolved 23.2\nJuniper Networks Junos OS Evolved 23.4\nJuniper Networks Junos OS Evolved 24.1",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:A/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": "Junos OS",
    "version": "23.2",
    "vendor": "Juniper Networks",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}