{"id":"UBUNTU-CVE-2026-42177","details":"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.","modified":"2026-05-27T19:15:07.217497657Z","published":"2026-05-12T18:17:00Z","upstream":["CVE-2026-42177"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-42177"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-42177"},{"type":"REPORT","url":"https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc"}],"affected":[{"package":{"name":"linux-entra-sso","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/linux-entra-sso?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.1-1","1.7.2-1","1.8.0-1"],"ecosystem_specific":{"binaries":[{"binary_name":"linux-entra-sso","binary_version":"1.8.0-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42177.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}