CVE-2026-25725 Claude Code Has Sandbox Escape via Persistent Configuration Injection in settings.json
Attackers can escape the sandbox and execute arbitrary code on the host by injecting persistent hooks into a missing configuration file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-25725?
CVE-2026-25725 is a high-severity code injection vulnerability in anthropics claude-code, published on 6 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-25725?
2 open source packages ship an affected version, including @anthropic-ai/claude-code. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@anthropic-ai/claude-code npm | All versions | 2.1.2 |
@anthropic-ai/claude-code npm | All versions | 2.1.2 |
Products include Anthropic Claude Code.
How do I fix CVE-2026-25725?
Upgrade @anthropic-ai/claude-code to 2.1.2 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-25725 being exploited?
There is no known exploitation of CVE-2026-25725 in the wild and no public exploit code.
Other vulnerabilities in anthropics claude-code
- CVE-2025-66032 Claude Code Command Validation Bypass Allows Arbitrary Code Execution
- CVE-2025-64755 @anthropic-ai/claude-code has Sed Command Validation Bypass that Allows Arbitrary File Writes
- CVE-2025-59536 Claude Code's startup trust dialog could lead to Command Execution attack
- CVE-2025-58764 Claude Code rg command had Command Injection that allowed bypass of user approval prompt for command execution
- CVE-2025-59041 Claude Code vulnerable to arbitrary code execution caused by maliciously configured git email
Sources
Also known as GHSA-ff64-7w26-62rf.