Security advisory

{
  "id": "e4ad87f7a6bc64191c165bafe0b35b36cda5f5990326160b60efa691ee50b417",
  "url": "https://osv.dev/vulnerability/CVE-2026-10054",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-10054",
    "summary": "In affected versions of Eclipse Theia (1.8.1 and later), the browser backend exposes privileged terminal RPC over WebSocket (/services/shell-terminal, /services/terminals/:id) without service-level authentication. WebSocket origin validation in @theia/core is fail-open: connections are accepted when the Origin header is missing or when no THEIA_HOSTS allowlist is configured (the default). The Socket.IO integration additionally replaces the real Origin header with a client-supplied fix-origin header that an attacker can control or omit. As a result, a foreign-origin web page visited by a user with a running Theia instance can open the /services WebSocket namespace, invoke terminal creation, attach to the resulting terminal data channel, execute arbitrary OS commands, and read their output. This affects both local developer setups (drive-by attack) and hosted or tunneled deployments without strong external authentication. A fix is in development that enforces same-origin validation by default, removes trust in the fix-origin header, gates HTTP and WebSocket access on a SameSite=Strict; HttpOnly connection-token cookie, and sanitizes shell terminal creation options.",
    "evidence": "osv:CVE-2026-10054",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-10054",
      "aliases": [
        "CVE-2026-10054",
        "GHSA-78g8-vm3p-97c6"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/eclipse-theia/theia",
              "type": "GIT",
              "events": [
                {
                  "introduced": "65edb153bd37f322a45c6c928d757e4090ba3265"
                },
                {
                  "fixed": "72573426f320fefc89a96ba55ce05c752d182123"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.8.1"
                      },
                      {
                        "fixed": "1.73.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-10054.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.938615519Z",
      "provider": "osv",
      "references": [
        "https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/376",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10054.json",
        "https://github.com/eclipse-theia/theia/security/advisories/GHSA-78g8-vm3p-97c6",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-10054"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1385",
          "CWE-306"
        ],
        "cna_assigner": "eclipse",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10054.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-10054",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491625,
  "published_at": "2026-07-03T10:11:32.446+00:00"
}