What is the CVSS score of CVE-2026-25725?

CVE-2026-25725 has a CVSS 3.1 base score of 10.0 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

How to fix or mitigate CVE-2026-25725?

Within 24 hours: Inventory all Claude Code deployments and identify systems running versions prior to 2.1.2; disable Claude Code if business-critical operations depend on it. Within 7 days: Implement network segmentation to isolate affected systems; enable detailed logging and monitoring for suspicious activities; contact Anthropic for patch timeline. Within 30 days: Apply vendor patch immediately upon release; validate sandbox functionality post-patch; conduct security review of affected systems for indicators of compromise.

Claude Code CVE-2026-25725

Q: Which versions of Claude Code are affected by CVE-2026-25725?

Claude Code versions prior to 2.1.2 contain a critical sandbox escape vulnerability (CVSS 10.0) that could allow attackers to access sensitive configuration data and potentially execute arbitrary…. A patch is available.

CRITICAL

Trust Boundary Violation (CWE-501)

2026-02-06 security-advisories@github.com

GHSA-ff64-7w26-62rf

Privilege Escalation RCE Linux Docker Code Injection AI / ML Claude Code Anthropic

10.0

CVSS 3.1 · GitHub Advisory

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Deploy malicious code in Claude Code workspace
Delivery

Execute code inside sandbox environment
Exploit

Create .claude/settings.json with injected hooks
Execution

Restart Claude Code instance
Impact

Execute persistent hooks with host privileges

Vulnerability Assessment

Weakness	CWE CWE-501 OWASP Top 10:2025 A06:2025 - Insecure Design ASVS 5.0 V14 - Data Protection Trust boundary enforcement
Exploitation Conditions	Claude Code version prior to 2.1.2 with .claude/settings.json file absent at startup. The parent .claude directory must be mounted as writable in the bubblewrap sandbox. No authentication required; exploitation occurs through malicious code execution within the sandbox environment.
Impact	CVSS 10.0 — maximum severity. Sandbox escape on developer workstations provides access to source code, credentials, SSH keys, and CI/CD pipeline secrets.
Exploit ScenarioDerived	Malicious code running within Claude Code's sandbox exploits the bubblewrap escape to access the host filesystem, steal SSH keys, API tokens, and source code from the developer's machine.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.

Patch available 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Claude Code prior to version 2.1.2 has a CVSS 10.0 sandbox escape in the bubblewrap sandboxing mechanism, allowing code execution outside the intended sandbox boundary.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:54 CVSS 10.0

CVSS 10.0 bubblewrap sandbox escape in Claude Code enables unrestricted code execution.

RemediationAI

Update Claude Code to 2.1.2+ immediately.

Affected Packages

npm @anthropic-ai/claude-code fix: 2.1.2

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in npm

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Claude Code < 2.1.2 has a CWE-501 trust boundary violation in its bubblewrap sandboxing mechanism that allows code executed within the sandbox to escape and run with the full privileges of the Claude Code process.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 10.0 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

CVE Published

Feb 06, 2026 - 18:16 nvd

CRITICAL 10.0

DescriptionGitHub Advisory

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.

Executive ViewAI

Why It Matters

Claude Code versions prior to 2.1.2 contain a critical sandbox escape vulnerability (CVSS 10.0) that could allow attackers to access sensitive configuration data and potentially execute arbitrary code on affected systems. Organizations using Claude Code must immediately assess deployment scope and implement containment measures, as no vendor patch is currently available.

Business Impact: Severe

Compensating Controls

Disable Claude Code until patch availability is confirmed; isolate affected systems from production networks and sensitive data; restrict Claude Code execution to dedicated, non-privileged user accounts; implement strict file system access controls to protect .claude/settings.json and related directories; monitor for unauthorized access attempts; consider air-gapping systems running vulnerable versions; implement application-level access controls to limit Claude Code functionality to essential operations only.

Threat Intelligence Overview

EPSS Score

0.1%

Top 81% exploitable

Data Quality

5 sources

Confidence: Medium

NVD

CVE.org

EPSS

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC No

EPSS 0.1%

Patch available Yes

Active threat No

Deciding rule

CRITICAL severity

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Out-of-Cycle

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

Very High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +50

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.

Code Injection CRITICAL

Code injection occurs when an application accepts user input and passes it directly into a language interpreter or evaluator without proper sanitization.

Remote Code Execution CRITICAL

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.