CVE-2026-25725: anthropic claude_code Trust Boundary Violation

Vulnerability summary

CVE-2026-25725 is a critical (CVSS 10.0) Trust Boundary Violation vulnerability in anthropic claude_code. EPSS estimates a 0.70% chance of exploitation in the next 30 days, higher than 52.6% of scored vulnerabilities.

Timeline

1. 06-02-2026
   PublishedVulnerability first disclosed.
2. 06-02-2026
   Last modifiedVulnerability information updated.

Description

Claude Code is an agentic coding tool. Prior to version 2.1.2, 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. This issue has been patched in version 2.1.2.

• CWE-501Trust Boundary ViolationThe product mixes trusted and untrusted data in the same data structure or structured message.
• CWE-668Exposure of Resource to Wrong SphereThe product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.