Unauthenticated remote code execution via HEEx template injection in phoenix_storybook playground_CVE-2026-8467

{
    "lastseen": "",
    "description": "Code Injection vulnerability in phenixdigital phoenix_storybook allows unauthenticated remote code execution via unsanitized attribute value interpolation in HEEx template generation.\n\nThe psb-assign WebSocket event handler in 'Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive':handle_event/3 accepts arbitrary attribute names and values from unauthenticated clients. These values are passed to 'Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers':handle_set_variation_assign/3, which stores them verbatim. When rendering, 'Elixir.PhoenixStorybook.Rendering.ComponentRenderer':attributes_markup/1 interpolates binary attribute values directly into a HEEx template string as name=\"<val>\" without escaping double quotes or HEEx expression delimiters. An attacker can supply a value containing a closing quote followed by a HEEx expression block (e.g. foo\" injected={EXPR} bar=\"), which causes EXPR to be treated as an inline Elixir expression. The resulting template is compiled via EEx.compile_string/2 and executed via Code.eval_quoted_with_env/3 with full Kernel imports and no sandbox, giving the attacker arbitrary code execution on the server.\n\nThis issue affects phoenix_storybook from 0.5.0 before 1.1.0.",
    "published": "2026-05-20T13:35:29.018Z",
    "modified": "2026-05-20T13:35:29.018Z",
    "type": "cve",
    "title": "Unauthenticated remote code execution via HEEx template injection in phoenix_storybook playground",
    "source": "EEF",
    "references": "https://github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-55hg-8qxv-qj4p\nhttps://cna.erlef.org/cves/CVE-2026-8467.html\nhttps://osv.dev/vulnerability/EEF-CVE-2026-8467\nhttps://github.com/phenixdigital/phoenix_storybook/commit/56ab8464d4375fa52db806148a06cce126ad481d",
    "id": "CVE-2026-8467",
    "bulletinFamily": "",
    "cwe": [
        "CWE-94"
    ],
    "cvelist": null,
    "sourceData": "phenixdigital phoenix_storybook 0.5.0\nphenixdigital phoenix_storybook e35379dfe2ef1a71b141899e36f431017c55265d",
    "sourceHref": "",
    "cvss": {
        "score": 9.5,
        "severity": "CRITICAL",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
        "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": "phoenix_storybook",
    "version": "0.5.0",
    "vendor": "phenixdigital",
    "ai_description": "Unauthenticated remote code execution via HEEx template injection in phoenix_storybook playground",
    "ai_severity": "Critical",
    "ai_vendor": "Phenixdigital",
    "ai_product": "phoenix_storybook",
    "ai_version": "0.5.0",
    "ai_score": 9.5
}