linux-entra-sso — security advisory

{
  "id": "bb08d44e288c588f493e423a576ea19acd82bfd3f1bf376d1af6092021bbf030",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-42177",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-42177",
    "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.",
    "evidence": "osv:UBUNTU-CVE-2026-42177",
    "products": [
      {
        "name": {
          "value": "linux-entra-sso",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.8.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.8.1-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.8.1-1ubuntu1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "linux-entra-sso",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.7.1-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.7.2-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.8.0-1",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-42177",
      "aliases": [
        "UBUNTU-CVE-2026-42177"
      ],
      "metrics": [
        {
          "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "linux-entra-sso",
            "purl": "pkg:deb/ubuntu/linux-entra-sso?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "1.8.0-1",
            "1.8.1-1",
            "1.8.1-1ubuntu1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42177.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "linux-entra-sso",
                "binary_version": "1.8.1-1ubuntu1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "linux-entra-sso",
            "purl": "pkg:deb/ubuntu/linux-entra-sso?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "1.7.1-1",
            "1.7.2-1",
            "1.8.0-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42177.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "linux-entra-sso",
                "binary_version": "1.8.0-1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:58:54.592784855Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-42177"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-42177",
        "https://www.cve.org/CVERecord?id=CVE-2026-42177",
        "https://github.com/siemens/linux-entra-sso/security/advisories/GHSA-52rj-42vh-2rxc"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-42177",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 359166,
  "published_at": "2026-05-12T18:17:00+00:00"
}