Junos OS and Junos OS Evolved: When telemetry collectors are frequently subscribing and unsubscribing to sensors chassisd or rpd will crash_CVE-2026-21921

{
    "lastseen": "",
    "description": "A Use After Free vulnerability in the chassis daemon (chassisd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based attacker authenticated with low privileges to cause a Denial-of-Service (DoS).\n\nWhen telemetry collectors are frequently subscribing and unsubscribing to sensors continuously over a long period of time, telemetry-capable processes like chassisd, rpd or mib2d will crash and restart, which - depending on the process - can cause a complete outage until the system has recovered.\n\nThis issue affects:\n\n\u00a0Junos OS:\u00a0\n\n\n\n  *  all versions before 22.4R3-S8,\n  *  23.2 versions before 23.2R2-S5,\n  *  23.4 versions before 23.4R2;\n\n\n\n\nJunos OS Evolved:\n\n\n\n  *  all versions before 22.4R3-S8-EVO,\n  *  23.2 versions before 23.2R2-S5-EVO,\n  *  23.4 versions before 23.4R2-EVO.",
    "published": "2026-01-15T20:28:29.656Z",
    "modified": "2026-01-15T20:55:25.182Z",
    "type": "cve",
    "title": "Junos OS and Junos OS Evolved: When telemetry collectors are frequently subscribing and unsubscribing to sensors chassisd or rpd will crash",
    "source": "juniper",
    "references": "https://supportportal.juniper.net/JSA106021\nhttps://kb.juniper.net/JSA106021",
    "id": "CVE-2026-21921",
    "bulletinFamily": "",
    "cwe": [
        "CWE-416"
    ],
    "cvelist": null,
    "sourceData": "Juniper Networks Junos OS 0\nJuniper Networks Junos OS 23.2\nJuniper Networks Junos OS 23.4\nJuniper Networks Junos OS Evolved 0\nJuniper Networks Junos OS Evolved 23.2\nJuniper Networks Junos OS Evolved 23.4",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/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": "0",
    "vendor": "Juniper Networks",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}