{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.0.74"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9ddce40de8c1ab71fb6303a125fdad0968dc1312"
            },
            {
              "fixed": "1ba15be4f0b0c9a026c0c7986668f8f2aa998440"
            }
          ],
          "repo": "https://github.com/anthropics/claude-code-action",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8q5r-mmjf-575q"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-200",
      "CWE-78"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47751.json"
  },
  "details": "Claude Code Action is a general-purpose GitHub action that runs Claude Code on GitHub pull requests and issues. Prior to 1.0.74, because the action checked out attacker-controlled pull request head branches, read .mcp.json from the working directory via default setting sources, and unconditionally enabled all project MCP servers via enableAllProjectMcpServers, an attacker who opened a pull request containing a malicious .mcp.json file could achieve arbitrary code execution on the GitHub Actions runner and exfiltrate secrets available to the workflow (such as API keys and tokens) when a privileged user or an automatic trigger invoked the Claude action on the pull request. This issue is fixed in version 1.0.74, which restores .claude/ and .mcp.json from the pull request base branch before the CLI runs.",
  "id": "CVE-2026-47751",
  "modified": "2026-08-12T03:51:45.585623549Z",
  "published": "2026-07-16T15:59:29.885Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/anthropics/claude-code-action/releases/tag/v1.0.74"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47751.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/anthropics/claude-code-action/security/advisories/GHSA-8q5r-mmjf-575q"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47751"
    },
    {
      "type": "FIX",
      "url": "https://github.com/anthropics/claude-code-action/commit/9ddce40de8c1ab71fb6303a125fdad0968dc1312"
    },
    {
      "type": "FIX",
      "url": "https://github.com/anthropics/claude-code-action/pull/1066"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Claude Code Action: Malicious MCP Server Configuration in PRs Enables Remote Code Execution and Secret Exfiltration"
}