Intel

CVE-2026-47751

anthropics/claude-code-action: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (CVE-2026-47751)

mediumEPSS 0.8%

Description

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.

Source: cvelistv5NVD (NIST)OSV (Open Source Vulnerabilities)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

github actionsanthropics/claude-code-action

Metrics

XIEM Effective CVSS
5.3
Source: nvd-v4
EPSS percentile
54.2 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
—
Show all metrics
Severity
medium
Priority score
72.32
Exploit maturity
no public PoC known
CVSS v4
5.3
EPSS score
0.8 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-07-16 15:59 UTC
CWE
CWE-78, CWE-200

Weakness classes (CWE)

  • CWE-78Base

    Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

    The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

    cwe.mitre.org →

  • CWE-200Class

    Exposure of Sensitive Information to an Unauthorized Actor

    The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

    cwe.mitre.org →

References & sources