argocd-mcp 0.8.0 Authentication Bypass via Unauthenticated HTTP

{
  "id": "53ba19a9ef9f8a02da871f7e34fd4e9c6417eb8daed2e6df19131253eb760b96",
  "url": "https://osv.dev/vulnerability/CVE-2026-82456",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "argocd-mcp 0.8.0 Authentication Bypass via Unauthenticated HTTP",
    "summary": "argocd-mcp 0.8.0 binds its HTTP transport to every network interface and accepts MCP sessions without requiring caller credentials when ARGOCD_API_TOKEN is configured. Attackers who can reach the listener can invoke the full tool surface using the operator's stored token to create applications, request syncs, and modify Argo CD resources.",
    "evidence": "osv:CVE-2026-82456",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-82456",
      "aliases": [
        "CVE-2026-82456",
        "GHSA-rp45-5x3v-48mr"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/argoproj-labs/mcp-for-argocd",
              "type": "GIT",
              "events": [
                {
                  "introduced": "25589071381e66505fd7e2da41f7b305b98bfd8c"
                },
                {
                  "fixed": "28d15ca69b0c31387cc6ec73d201fd13c5d22b6a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.8.0"
                      },
                      {
                        "fixed": "0.9.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.8.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-82456.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.462777479Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82456.json",
        "https://github.com/argoproj-labs/mcp-for-argocd/security/advisories/GHSA-rp45-5x3v-48mr",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-82456",
        "https://www.vulncheck.com/advisories/argocd-mcp-0.8.0-authentication-bypass-via-unauthenticated-http",
        "https://github.com/argoproj-labs/mcp-for-argocd"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1327"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82456.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-82456",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492965,
  "published_at": "2026-08-29T13:47:57.447+00:00"
}