CVE-2026-46406
Claude Code: Insecure Temporary File in /copy Command Enables Response Disclosure and Symlink-Based File Write
Description
Claude Code is an agentic coding tool. From 2.1.59 until 2.1.128, 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. Exploiting this required a local unprivileged user on the same system and a privileged user to run the /copy command. This vulnerability is fixed in 2.1.128.
INFO
Published Date :
June 29, 2026, 3:16 p.m.
Last Modified :
Oct. 25, 2026, 9:10 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-46406
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Claude Code to version 2.1.128.
- Ensure file permissions and directory access are restricted.
- Avoid writing sensitive data to predictable paths.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-46406.
| URL | Resource |
|---|---|
| https://github.com/anthropics/claude-code/security/advisories/GHSA-4vp2-6q8c-pvq2 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-46406 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-46406
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-46406 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-46406 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: claude-code de anthropics, Description: Claude Code es una herramienta de codificación agéntica. Desde la versión 2.1.59 hasta la 2.1.128, el comando /copy de Claude Code escribía las respuestas en una ruta codificada de forma rígida y predecible (/tmp/claude/response.md) sin aislamiento de UID, aleatoriedad o protección contra enlaces simbólicos. El archivo se creaba con permisos de lectura para todos (0644) en un directorio transitable por todos (0755), lo que permitía a cualquier usuario local leer la respuesta de Claude de un usuario privilegiado, que podría contener secretos o credenciales. Además, debido a que la ruta era estática y predecible, un atacante local podría pre-crear el directorio y colocar un enlace simbólico en la ruta de archivo esperada, haciendo que el proceso privilegiado siguiera el enlace simbólico y sobrescribiera un archivo elegido por el atacante con el texto de la respuesta. Explotar esto requería un usuario local sin privilegios en el mismo sistema y un usuario privilegiado para ejecutar el comando /copy. Esta vulnerabilidad está corregida en la versión 2.1.128. -
Initial Analysis by [email protected]
Jun. 30, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H Added CPE Configuration OR *cpe:2.3:a:anthropic:claude_code:*:*:*:*:*:node.js:*:* versions from (including) 2.1.58 up to (excluding) 2.1.128 Added Reference Type GitHub, Inc.: https://github.com/anthropics/claude-code/security/advisories/GHSA-4vp2-6q8c-pvq2 Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 29, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-46406', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-29T15:25:46.123210Z'} -
New CVE Received by [email protected]
Jun. 29, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'anthropics', 'product': 'claude-code', 'versions': [{'status': 'affected', 'version': '>= 2.1.59, < 2.1.128'}]}] Added Description Claude Code is an agentic coding tool. From 2.1.59 until 2.1.128, 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. Exploiting this required a local unprivileged user on the same system and a privileged user to run the /copy command. This vulnerability is fixed in 2.1.128. Added CVSS V4.0 AV:L/AC:L/AT:P/PR:L/UI:A/VC:L/VI:L/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 Added CWE CWE-200 Added CWE CWE-59 Added CWE CWE-377 Added Reference https://github.com/anthropics/claude-code/security/advisories/GHSA-4vp2-6q8c-pvq2