CVE-2026-47751
- Source
- https://cve.org/CVERecord?id=CVE-2026-47751
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-47751.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-47751
- Aliases
- Published
- 2026-07-16T15:59:29Z
- Modified
- 2026-10-28T02:30:28Z
- Severity
-
- 5.3 (Medium) CVSS_V4 - 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 CVSS Calculator
- Summary
- Claude Code Action: Malicious MCP Server Configuration in PRs Enables Remote Code Execution and Secret Exfiltration
- 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.
- 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" }- References
-
- https://github.com/anthropics/claude-code-action/releases/tag/v1.0.74
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47751.json
- https://github.com/anthropics/claude-code-action/security/advisories/GHSA-8q5r-mmjf-575q
- https://nvd.nist.gov/vuln/detail/CVE-2026-47751
- https://github.com/anthropics/claude-code-action/commit/9ddce40de8c1ab71fb6303a125fdad0968dc1312
- https://github.com/anthropics/claude-code-action/pull/1066
Affected packages
Git / github.com/anthropics/claude-code-action
Affected ranges
- Type
- GIT
- Repo
- https://github.com/anthropics/claude-code-action
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixedFixed
- Database specific
-
Show details
{ "extracted_events": [ { "range": [ { "introduced": "0" }, { "fixed": "1.0.74" } ], "source": "AFFECTED_FIELD", "strategy": "StringRangeExpression" }, { "range": [ { "fixed": "9ddce40de8c1ab71fb6303a125fdad0968dc1312" } ], "source": "REFERENCES_COMMIT" }, { "original_tag": "v1.0.74", "range": [ { "fixed": "1ba15be4f0b0c9a026c0c7986668f8f2aa998440" } ], "source": "REFERENCES_TAG" } ] }