CVE-2026-42177 (GCVE-0-2026-42177)

Vulnerability from cvelistv5 – Published: 2026-05-12 17:11 – Updated: 2026-05-13 14:37
VLAI
Title
linux-entra-sso: PRT SSO cookie can leak to attacker-controlled hosts when broad host permissions are granted
Summary
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.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-13 14:35 UTC
CWE
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 8094 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
siemens linux-entra-sso Affected: < 1.8.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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