CVE-2026-47751

MEDIUMPre-NVD 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 0%CVSS: —Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Claude Code Action: Malicious MCP Server Configuration in PRs Enables Remote Code Execution and Secret Exfiltration

Due to the combination of checking out PR head branches (attacker-controlled), reading .mcp.json from the working directory via default setting sources, and unconditionally enabling all project MCP servers via enableAllProjectMcpServers, it was possible for an attacker who opened a PR containing a malicious .mcp.json file to achieve arbitrary code execution on the GitHub Actions runner. This could lead to exfiltration of secrets available to the workflow (such as API keys and tokens) when a privileged user triggered the Claude action on the PR. Exploiting this required the ability to open a pull request against a repository using the claude-code-action and a privileged user or automatic trigger to invoke the action on that PR.

Users pinned to a vulnerable version of claude-code-action are advised to update to the latest version. Users referencing anthropics/claude-code-action@v1, anthropics/claude-code-action@beta, anthropics/claude-code-action@main, or other non-pinned tags will have received this fix already

Claude Code thanks hackerone.com/reptou for reporting this issue.

CVSS v3
—
EG Score
0.0(none)
EPSS
21.6%
KEV
Not listed

Published

June 10, 2026

Last Modified

June 10, 2026

Vendor Advisories for CVE-2026-47751(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 0× in last 7d / 5× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-06-14 23:18 UTCEPSS rescore
  2. 2026-06-13 23:00 UTCEPSS rescore
  3. 2026-06-13 16:01 UTCEG score recompute
  4. 2026-06-12 23:12 UTCEPSS rescore
  5. 2026-06-10 20:17 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-47751?
CVE-2026-47751 is a medium vulnerability published on June 10, 2026. Claude Code Action: Malicious MCP Server Configuration in PRs Enables Remote Code Execution and Secret Exfiltration Due to the combination of checking out PR head branches (attacker-controlled), reading .mcp.json from the working directory via default setting sources, and unconditionally enabling…
When was CVE-2026-47751 disclosed?
CVE-2026-47751 was first published in the National Vulnerability Database on June 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47751 actively exploited?
CVE-2026-47751 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2026-47751?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47751, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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