CVE-2026-47751 (GCVE-0-2026-47751)
Vulnerability from cvelistv5 – Published: 2026-07-16 15:59 – Updated: 2026-07-18 02:55
VLAI
EPSS
VEX
Title
Claude Code Action: Malicious MCP Server Configuration in PRs Enables Remote Code Execution and Secret Exfiltration
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-18 02:55 UTC
CWE
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/anthropics/claude-code-action/… | x_refsource_CONFIRM |
| https://github.com/anthropics/claude-code-action/… | x_refsource_MISC |
| https://github.com/anthropics/claude-code-action/… | x_refsource_MISC |
| https://github.com/anthropics/claude-code-action/… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| anthropics | claude-code-action |
Affected:
< 1.0.74
|
guessed |
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"lastModified": "2026-07-18T03:16:36.220",
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