{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.22.0"
              },
              {
                "fixed": "1.1.2"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "6a57e75d729f9767827bc4f96e80ff9bd8538a46"
            },
            {
              "fixed": "b5397f6e3305531a1c534b90b2d347a70fa84da9"
            }
          ],
          "repo": "https://github.com/github/github-mcp-server",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-pjp5-fpmr-3349"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-284"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48529.json"
  },
  "details": "GitHub MCP Server is GitHub's official MCP Server. From 0.22.0 until 1.1.2, when running in HTTP mode with --lockdown-mode enabled, the RepoAccessCache is implemented as a process-global singleton initialized with the first authenticated user's GraphQL client. All subsequent requests from different users share this singleton and their lockdown-related GraphQL queries are executed using the first user's credentials. The singleton is never updated to reflect later users' tokens. This vulnerability is fixed in 1.1.2.",
  "id": "CVE-2026-48529",
  "modified": "2026-07-15T01:49:12.264325433Z",
  "published": "2026-06-26T16:33:32.688Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48529.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48529"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion"
}