OpenYak local API: unauthenticated CSRF chain leads to Remote Code Execution

{
  "id": "508996ec97f44e015308635593bde1e1d57ac370372dcc5fff8947a9ccfe4fd3",
  "url": "https://osv.dev/vulnerability/CVE-2026-46409",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "OpenYak local API: unauthenticated CSRF chain leads to Remote Code Execution",
    "summary": "OpenYak is a local-first agent runtime for reliable tool-using models, with a desktop workspace built on top. Prior to version 1.1.3, the OpenYak desktop backend binds an HTTP API to `127.0.0.1:` (commonly 19141) without server-side Origin validation, loopback authentication, or Content-Type enforcement, and with a wildcard CORS policy. Any webpage a user visits while OpenYak is running can issue cross-origin requests to this local server — the browser acts as a proxy into loopback, bypassing OS-level network isolation. Chained, this lets a malicious page execute arbitrary shell commands on the host (RCE) via the build agent with `permission_presets.bash=true`, shut down the service, and exfiltrate chat history and account PII — with no user interaction beyond opening the page. Version 1.1.3 patches the issue.",
    "evidence": "osv:CVE-2026-46409",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-46409",
      "aliases": [
        "CVE-2026-46409",
        "GHSA-ccxp-q2w5-27jw"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/openyak/openyak",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "b57cb51e4ed77b2815c4a984036c58fd42b9ccf0"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.1.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.1.3"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.1.2",
            "v1.1.1",
            "v1.1.0",
            "v1.0.8",
            "v1.0.7",
            "v1.0.6",
            "v1.0.5",
            "v1.0.4",
            "v1.0.3",
            "v1.0.2"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46409.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.404700534Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46409.json",
        "https://github.com/openyak/openyak/security/advisories/GHSA-ccxp-q2w5-27jw",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-46409"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-306",
          "CWE-346",
          "CWE-352",
          "CWE-94",
          "CWE-942"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46409.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-46409",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 513289,
  "published_at": "2026-08-07T22:11:57.765+00:00"
}