Anthropic Claude Code 2.1.59 < 2.1.128 Information Disclosure (CVE-2026-46406)

medium Nessus Plugin ID 324950

Synopsis

An application installed on the remote host is affected by an information disclosure vulnerability.

Description

The version of Anthropic Claude Code installed on the remote host is 2.1.59 prior to 2.1.128. It is, therefore, affected by an information disclosure vulnerability:

- The Claude Code /copy command wrote responses to a hardcoded, predictable path (/tmp/claude/response.md) without UID isolation, randomness, or symlink protection. The file was created world-readable (0644) in a world-traversable directory (0755), allowing any local user to read a privileged user's Claude response, which could contain secrets or credentials.
Additionally, because the path was static and predictable, a local attacker could pre-create the directory and plant a symlink at the expected file path, causing the privileged process to follow the symlink and overwrite an attacker-chosen file with the response text. (CVE-2026-46406)

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 2.1.128 or later.

Plugin Details

Severity: Medium

ID: 324950

File Name: anthropic_claude_code_CVE-2026-46406.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: Low

Score: 3.9

Percentile: 52.78

CVSS v2

Risk Factor: Medium

Base Score: 5.6

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

CVSS Score Source: CVE-2026-46406

CVSS v3

Risk Factor: High

Base Score: 7.1

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

CVSS v4

Risk Factor: Medium

Base Score: 4.4

Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:L/VI:L/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-2026-46406

Detections

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