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CVE-2026-47751

MEDIUM
5.3
CVSS 4.0
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.

Metadata

CVE ID
CVE-2026-47751
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-05-19 22:16 UTC
Published
2026-07-16 15:59 UTC
Last updated
2026-07-16 15:59 UTC
Primary CWE
CWE-78
CWE-78: Improper Neutralization of Special Elements used in …
Vendor / Product
anthropics / claude-code-action
Sources
cve.org  ·  NVD

Severity & Metrics

5.3 MEDIUM CVSS 4.0
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
Affected products (1)
VendorProductPlatformVersions
anthropics claude-code-action — < 1.0.74
Weakness (CWE)
CWESourceDescription
CWE-200 cna CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
CWE-78 cna CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVSS scores (1)
ScoreSeverityVersionSourceVector
5.3 MEDIUM 4.0 cna 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
References (4)
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