linux-entra-sso: PRT SSO cookie can leak to attacker-controlled hosts when broad host permissions are granted_CVE-2026-42177

{
    "lastseen": "",
    "description": "linux-entra-sso is a browser plugin for Linux to SSO on Microsoft Entra ID. Prior to 1.8.1, platform/chrome/js/platform-chrome.js:69-88 registers a single declarativeNetRequest rule whose urlFilter is Platform.SSO_URL + \"/*\", i.e. \"https://login.microsoftonline.com/*\". Chrome's urlFilter without a | or || anchor is substring-matched against the full request URL. The same applied rule action is modifyHeaders that attaches the Entra ID Primary Refresh Token cookie. The Firefox adapter in platform/firefox/js/platform-firefox.js:53 performs a belt-and-braces startsWith(Platform.SSO_URL) check before injecting the header; the Chrome adapter does not. When the extension holds broad host permissions through the optional_host_permissions: [\"https://*/*\"] declared in platform/chrome/manifest.json:34, a main-frame navigation to a URL whose path embeds https://login.microsoftonline.com/ causes Chrome to attach the PRT cookie to the request to the attacker-controlled host. This vulnerability is fixed in 1.8.1.",
    "published": "2026-05-12T17:11:36.050Z",
    "modified": "2026-05-12T17:11:36.050Z",
    "type": "cve",
    "title": "linux-entra-sso: PRT SSO cookie can leak to attacker-controlled hosts when broad host permissions are granted",
    "source": "GitHub_M",
    "references": "https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc",
    "id": "CVE-2026-42177",
    "bulletinFamily": "",
    "cwe": [
        "CWE-284",
        "CWE-436"
    ],
    "cvelist": null,
    "sourceData": "siemens linux-entra-sso < 1.8.1",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N",
        "version": "3.1"
    },
    "cvss2": [],
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        "confidentialityImpact": "",
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        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "linux-entra-sso",
    "version": "< 1.8.1",
    "vendor": "siemens",
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    "ai_score": 0
}