{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.74.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "172494ea2564ca07690e230805861146007fae79"
            }
          ],
          "repo": "https://github.com/eclipse-theia/theia",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-qqc8-9538-25v4"
  ],
  "database_specific": {
    "cna_assigner": "eclipse",
    "cwe_ids": [
      "CWE-200",
      "CWE-22",
      "CWE-306",
      "CWE-36"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61891.json"
  },
  "details": "In Eclipse Theia versions up to and including 1.73.1, the `@theia/filesystem` backend exposes HTTP file-download endpoints (`GET /file`, `GET /files/`, `PUT /files/`) that convert a client-supplied URI directly to a filesystem path and stream the file, without confining it to the workspace or any allow-listed root. In browser (non-Electron) deployments the connection token is enforced only on WebSocket upgrades; the HTTP middleware in `@theia/core` re-issues the cookie and calls `next()` without rejecting tokenless HTTP requests, so these endpoints are reachable without a valid token. As a result an unauthenticated client can read any file readable by the backend process, including files outside the opened workspace (for example `/etc/hosts`, SSH keys, or tokens). Electron mode uses a separate `ElectronSecurityToken` and is not affected via this path.",
  "id": "CVE-2026-61891",
  "modified": "2026-08-09T03:30:36.965928324Z",
  "published": "2026-08-05T11:03:01.669Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/176"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61891.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-9538-25v4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-61891"
    },
    {
      "type": "REPORT",
      "url": "https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/570"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}