Detections
Analytics

Anthropic Claude Code 2.1.38 < 2.1.163 Sandbox Escape (CVE-2026-55607)

high Nessus Plugin ID 324951

Synopsis

An application installed on the remote host is affected by a sandbox escape vulnerability.

Description

The version of Anthropic Claude Code installed on the remote host is 2.1.38 prior to 2.1.163. It is, therefore, affected by a sandbox escape vulnerability:

 - Claude Code's worktree handling allowed creation of worktrees named '.git' and navigation to worktrees outside the sandbox context, enabling git directory confusion attacks. By exploiting symlink manipulation and git fsmonitor execution during worktree operations, an attacker could overwrite files in the user's home directory (such as .zshenv), leading to code execution outside of seatbelt sandbox restrictions. Reliably exploiting this required the user to clone a malicious repository containing prompt injection content and run Claude Code against it.
 (CVE-2026-55607)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade Anthropic Claude Code to version 2.1.163 or later.

See Also

http://www.nessus.org/u?f335f8e3

Plugin Details

Severity: High

ID: 324951

File Name: anthropic_claude_code_CVE-2026-55607.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 7/3/2026

Updated: 7/3/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.03

CVSS v2

Risk Factor: High

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2026-55607

CVSS v3

Risk Factor: Critical

Base Score: 9.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS v4

Risk Factor: High

Base Score: 7.7

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

Vulnerability Information

CPE: cpe:/a:anthropic:claude_code

Required KB Items: installed_sw/Anthropic Claude Code

Patch Publication Date: 6/25/2026

Vulnerability Publication Date: 6/25/2026

Reference Information

CVE: CVE-2026-55607