CVE-2026-47751

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-16 17:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-24 20:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-16 17:16 UTC

Last modified

2026-10-24 20:10 UTC

Exploit probability

0.8% · EPSS, next 30 days

Weakness

CWE-78 · OS command injection

Record status

Awaiting Analysis

Attack profile CVSS 4.0 · 5.3

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

Low

User interaction

None

Confidentiality

Low

Integrity

Low

Availability

None