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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-ff64-7w26-62rf Claude Code has Sandbox Escape via Persistent Configuration Injection in settings.json
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 06 Feb 2026 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 06 Feb 2026 18:15:00 +0000

Type Values Removed Values Added
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.
Title Claude Code Has Sandbox Escape via Persistent Configuration Injection in settings.json
Weaknesses CWE-501
CWE-668
References
Metrics cvssV4_0

{'score': 7.7, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-06T19:15:02.998Z

Reserved: 2026-02-05T16:48:00.426Z

Link: CVE-2026-25725

cve-icon Vulnrichment

Updated: 2026-02-06T19:14:58.348Z

cve-icon NVD

Status : Received

Published: 2026-02-06T18:16:00.187

Modified: 2026-02-06T18:16:00.187

Link: CVE-2026-25725

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses