GitHub Advisoryadvisory · npm

GHSA-ff64-7w26-62rf Claude Code has Sandbox Escape via Persistent Configuration Injection in settings.json

HIGH Published 2026-02-06 Modified 2026-02-06 Official page ↗
Aliases
CVE-2026-25725
Ecosystem
npm
Packages
@anthropic-ai/claude-code
Severity
High
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Weaknesses
CWE-501, CWE-668
Reviewed
2026-02-06

Affected packages

• npm @anthropic-ai/claude-code: < 2.1.2 → fixed in 2.1.2

Description

Claude Code's bubblewrap sandboxing mechanism failed to properly protect the .claude/settings.json configuration file when it did not exist at startup. While the parent directory was mounted as writable and .claude/settings.local.json was explicitly protected with read-only constraints, settings.json was not protected if it was missing. This allowed malicious code running inside the sandbox to create this file and inject persistent hooks (such as SessionStart commands) that would execute with host privileges when Claude Code was restarted. Users on standard Claude Code auto-update received this fix automatically. Users performing manual updates are advised to update to the latest version. Claude Code thanks hackerone.com/edbr for reporting this issue!

Related

Alias · CVE (1)

Weakness · CWE (2)

  • CWE-501 Trust Boundary Violation weakness
  • CWE-668 Exposure of Resource to Wrong Sphere weakness

References