Docker Sandboxes network egress allowlist bypass via unfiltered DNS resolution_CVE-2026-12039

{
    "lastseen": "",
    "description": "Docker Sandboxes (sbx) enforces an HTTP/S-only egress allowlist but does not apply it to DNS resolution: the per-network embedded DNS server forwards any queried name to the host resolver whenever the network is internet-connected, without consulting the policy. A workload inside a sandbox, which the threat model treats as untrusted, can therefore encode data into DNS labels for an attacker-controlled domain and exfiltrate it through a DNS covert channel, bypassing the configured allowlist.",
    "published": "2026-06-18T13:48:14.682Z",
    "modified": "2026-06-18T15:00:24.095Z",
    "type": "cve",
    "title": "Docker Sandboxes network egress allowlist bypass via unfiltered DNS resolution",
    "source": "Docker",
    "references": "https://docs.docker.com/ai/sandboxes/\nhttps://github.com/docker/sbx-releases/releases/tag/v0.33.0",
    "id": "CVE-2026-12039",
    "bulletinFamily": "",
    "cwe": [
        "CWE-923"
    ],
    "cvelist": null,
    "sourceData": "Docker Docker Sandboxes 0.13.0",
    "sourceHref": "",
    "cvss": {
        "score": 5.7,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "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": "Docker Sandboxes",
    "version": "0.13.0",
    "vendor": "Docker",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}