Security advisory

{
  "id": "f6120e07f5d0333622a861564a21071284fa6122fd103b3afb81d3d15bd7c18d",
  "url": "https://osv.dev/vulnerability/CVE-2021-34435",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-34435",
    "summary": "In Eclipse Theia 0.3.9 to 1.8.1, the \"mini-browser\" extension allows a user to preview HTML files in an iframe inside the IDE. But with the way it is made it is possible for a previewed HTML file to trigger an RCE. This exploit only happens if a user previews a malicious file..",
    "evidence": "osv:CVE-2021-34435",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-34435",
      "aliases": [
        "CVE-2021-34435",
        "GHSA-v9w2-v7j9-rjpr"
      ],
      "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": "7caa4c877661849f4e460055a2ca1695a2593b23"
                },
                {
                  "last_affected": "65edb153bd37f322a45c6c928d757e4090ba3265"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.3.9"
                      },
                      {
                        "last_affected": "1.8.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.8.1",
            "v1.8.0",
            "v1.7.0",
            "v1.6.0",
            "v1.5.0",
            "v1.4.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.0",
            "v0.16.0",
            "v0.15.0",
            "v0.14.0",
            "v0.13.0",
            "v0.12.0",
            "v0.11.0",
            "v0.10.0",
            "v0.9.0",
            "v0.8.0",
            "v0.7.0",
            "v0.6.0",
            "v0.5.0",
            "v0.4.0",
            "v0.3.19",
            "v0.3.18",
            "v0.3.17",
            "v0.3.16",
            "v0.3.15",
            "v0.3.14",
            "v0.3.13",
            "v0.3.12",
            "v0.3.11",
            "v0.3.10",
            "v0.3.9"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-34435.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:27.405444827Z",
      "provider": "osv",
      "references": [
        "https://bugs.eclipse.org/bugs/show_bug.cgi?id=568018"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-34435",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 431825,
  "published_at": "2021-09-01T18:15:09.107+00:00"
}