GHSA-ff64-7w26-62rf CVE-2026-25725
Claude Code has Sandbox Escape via Persistent Configuration Injection in settings.json
- Severity
- 0.0 / 10
- Critical · CVSS 4.0
- Exploit chance (EPSS)
- 0.54%
- Chance of exploitation in the next 30 days. Higher than 45.26% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Fix
2.1.2- Upgrade @anthropic-ai/claude-code to this version or later
Description
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.
Users on standard Claude Code auto-update received this fix automatically. Users performing manual updates are advised to update to the latest version.
Claude Code thanks hackerone.com/edbr for reporting this issue!
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| @anthropic-ai/claude-code | < 2.1.2 |
2.1.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
@anthropic-ai/claude-code npm → 2.1.2
- npm
npm install @anthropic-ai/claude-code@2.1.2- yarn
yarn add @anthropic-ai/claude-code@2.1.2- pnpm
pnpm add @anthropic-ai/claude-code@2.1.2
Severity breakdown
CVSS 4.0 0.0
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
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- Passive
- Confidentiality (vulnerable system)
- High
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- High
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
CVSS 3.1 10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-501: Trust Boundary Violation
The product mixes trusted and untrusted data in the same data structure or structured message.
CWE-668: Exposure of Resource to Wrong Sphere
The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-pq7j-f95f-qfcv Claude Code: Plugin Hash Pin Bypass Allows Bypass of Hash Pinning | High | Also affects @anthropic-ai/claude-code |
| GHSA-7835-87q9-rgvv Claude Code: Sandbox Escape via Git Worktree Path Confusion Allows Unsandboxed Code Execution | High | Also affects @anthropic-ai/claude-code |
| GHSA-4vp2-6q8c-pvq2 @anthropic-ai/claude-code has an Insecure Temporary File in /copy Command that Enables Response Disclosure and Symlink-Based File Write | Medium | Also affects @anthropic-ai/claude-code |
| GHSA-fg94-h982-f3mm Claude Code: Out-of-Band Data Exfiltration via Pre-Approved HuggingFace Domain in WebFetch | Critical | Also affects @anthropic-ai/claude-code |
| GHSA-q5hj-mxqh-vv77 Claude Code: Trust Dialog Bypass via Git Worktree Spoofing Allows Arbitrary Code Execution | High | Also affects @anthropic-ai/claude-code |
| GHSA-vp62-r36r-9xqp Claude Code: Sandbox Escape via Symlink Following Allows Arbitrary File Write Outside Workspace | Critical | Also affects @anthropic-ai/claude-code |
| GHSA-5cwg-9f6j-9jvx Claude Code: Insecure System-Wide Configuration Loading Enables Local Privilege Escalation on Windows | High | Also affects @anthropic-ai/claude-code |
| GHSA-mmgp-wc2j-qcv7 Claude Code has a Workspace Trust Dialog Bypass via Repo-Controlled Settings File | High | Also affects @anthropic-ai/claude-code |
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