CVE-2026-42177

{
  "id": "CVE-2026-42177",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-12T18:17:24.240",
  "lastModified": "2026-10-26T18:10:00.173",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    },
    {
      "lang": "es",
      "value": "linux-entra-sso es un plugin de navegador para Linux para SSO en Microsoft Entra ID. Antes de 1.8.1, platform/chrome/js/platform-chrome.js:69-88 registra una única regla de declarativeNetRequest cuyo urlFilter es Platform.SSO_URL + ’/*’, es decir, ’https://login.microsoftonline.com/*’. El urlFilter de Chrome sin un ancla | o || se compara como subcadena con la URL completa de la solicitud. La misma acción de regla aplicada es modifyHeaders que adjunta la cookie del token de actualización principal de Entra ID. El adaptador de Firefox en platform/firefox/js/platform-firefox.js:53 realiza una comprobación de doble seguridad startsWith(Platform.SSO_URL) antes de inyectar la cabecera; el adaptador de Chrome no lo hace. Cuando la extensión tiene permisos de host amplios a través de optional_host_permissions: [’https://*/*’] declarado en platform/chrome/manifest.json:34, una navegación de marco principal a una URL cuya ruta incrusta https://login.microsoftonline.com/ hace que Chrome adjunte la cookie PRT a la solicitud al host controlado por el atacante. Esta vulnerabilidad está corregida en 1.8.1."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "siemens",
          "product": "linux-entra-sso",
          "versions": [
            {
              "version": "< 1.8.1",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-13T14:35:33.712997Z",
          "id": "CVE-2026-42177",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-284"
        },
        {
          "lang": "en",
          "value": "CWE-436"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}