{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42177","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-04-25T01:53:21.582Z","datePublished":"2026-05-12T17:11:36.050Z","dateUpdated":"2026-05-13T14:37:56.682Z"},"containers":{"cna":{"title":"linux-entra-sso: PRT SSO cookie can leak to attacker-controlled hosts when broad host permissions are granted","problemTypes":[{"descriptions":[{"cweId":"CWE-284","lang":"en","description":"CWE-284: Improper Access Control","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-436","lang":"en","description":"CWE-436: Interpretation Conflict","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc","tags":["x_refsource_CONFIRM"],"url":"https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc"}],"affected":[{"vendor":"siemens","product":"linux-entra-sso","versions":[{"version":"< 1.8.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-05-12T17:11:36.050Z"},"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."}],"source":{"advisory":"GHSA-52rj-42vh-2rxc","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc"}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-13T14:35:33.712997Z","id":"CVE-2026-42177","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-13T14:37:56.682Z"}}]}}