{"api_version":"1","generated_at":"2026-05-13T00:13:58+00:00","cve":"CVE-2026-42177","urls":{"html":"https://cve.report/CVE-2026-42177","api":"https://cve.report/api/cve/CVE-2026-42177.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-42177","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-42177"},"summary":{"title":"linux-entra-sso: PRT SSO cookie can leak to attacker-controlled hosts when broad host permissions are granted","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.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-05-12 18:17:24","updated_at":"2026-05-12 18:17:24"},"problem_types":["CWE-284","CWE-436","CWE-284 CWE-284: Improper Access Control","CWE-436 CWE-436: Interpretation Conflict"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","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","data":{"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"}},{"version":"3.1","source":"CNA","type":"DECLARED","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","data":{"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":[{"url":"https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc","name":"https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-42177","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42177","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"siemens","product":"linux-entra-sso","version":"affected < 1.8.1","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"linux-entra-sso","vendor":"siemens","versions":[{"status":"affected","version":"< 1.8.1"}]}],"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."}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-284","description":"CWE-284: Improper Access Control","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-436","description":"CWE-436: Interpretation Conflict","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-12T17:11:36.050Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"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"}],"source":{"advisory":"GHSA-52rj-42vh-2rxc","discovery":"UNKNOWN"},"title":"linux-entra-sso: PRT SSO cookie can leak to attacker-controlled hosts when broad host permissions are granted"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-42177","datePublished":"2026-05-12T17:11:36.050Z","dateReserved":"2026-04-25T01:53:21.582Z","dateUpdated":"2026-05-12T17:11:36.050Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-12 18:17:24","lastModifiedDate":"2026-05-12 18:17:24","problem_types":["CWE-284","CWE-436","CWE-284 CWE-284: Improper Access Control","CWE-436 CWE-436: Interpretation Conflict"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","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}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"42177","Ordinal":"1","Title":"linux-entra-sso: PRT SSO cookie can leak to attacker-controlled ","CVE":"CVE-2026-42177","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"42177","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"linux-entra-sso: PRT SSO cookie can leak to attacker-controlled "}]}}}