Host code execution via unprotected settings creation
Published Feb 6, 2026 · Updated Feb 6, 2026
Sandbox escape in Anthropic Claude Code before 2.1.2 allows remote attackers to execute persistent hooks with host privileges. Bubblewrap leaves .claude/settings.json creatable when it is absent at startup because the writable parent directory is mounted without a read-only constraint for that missing file. Exploitation requires sandboxed malicious code, an absent file at startup, and a later Claude Code restart; injected commands then run outside the sandbox.
Summary
What happened
Sandbox escape in Anthropic Claude Code before 2.1.2 allows remote attackers to execute persistent hooks with host privileges. Bubblewrap leaves .claude/settings.json creatable when it is absent at startup because the writable parent directory is mounted without a read-only constraint for that missing file. Exploitation requires sandboxed malicious code, an absent file at startup, and a later Claude Code restart; injected commands then run outside the sandbox.
The record
- CVE
- CVE-2026-25725
- Published
- Feb 6, 2026
- Updated
- Feb 6, 2026
- Vendor
- Anthropic
- Product
- Claude Code
- Classifications
- CWE-501, CWE-668, T1546
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 6, 2026CVE publishedPublication date reported by the CVE source.
- Feb 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.1.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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