Vulnerability Report

CVE-2026-25725

Title: Sandbox escape in Claude Code bubblewrap sandboxing mechanism

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-25725.

CWE Category CWE-501

Published Date Feb 06, 2026

Modified Date Feb 09, 2026

Exploit Status Not Found

Score 7.7 CVSS v4.0

Exploit Probability (EPSS)

0.42%

Vulnerability Summary

CVE-2026-25725: 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.

Impacted Vendors

anthropic 1

Reference Links

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

CVSS v4.0

Source Entity [email protected]

Severity HIGH

7.7

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

PASSIVE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1

Source Entity [email protected]

Severity CRITICAL

10.0

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns