CVE-2026-46406 Claude Code: Insecure Temporary File in /copy Command Enables Response Disclosure and Symlink-Based File Write
Local attackers can read privileged user responses or overwrite arbitrary files via symlink attacks due to insecure temporary file handling in the /copy command.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-46406?
CVE-2026-46406 is a medium-severity path traversal vulnerability in anthropics claude-code, published on 29 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-46406?
2 open source packages ship an affected version, including @anthropic-ai/claude-code. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@anthropic-ai/claude-code npm | From 2.1.59 | 2.1.128 |
@anthropic-ai/claude-code npm | From 2.1.59 | 2.1.128 |
Products include Anthropic Claude Code.
How do I fix CVE-2026-46406?
Upgrade @anthropic-ai/claude-code to 2.1.128 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-46406 being exploited?
There is no known exploitation of CVE-2026-46406 in the wild and no public exploit code.
Other vulnerabilities in anthropics claude-code
- CVE-2025-66032 Claude Code Command Validation Bypass Allows Arbitrary Code Execution
- CVE-2025-64755 @anthropic-ai/claude-code has Sed Command Validation Bypass that Allows Arbitrary File Writes
- CVE-2025-59536 Claude Code's startup trust dialog could lead to Command Execution attack
- CVE-2025-58764 Claude Code rg command had Command Injection that allowed bypass of user approval prompt for command execution
- CVE-2025-59041 Claude Code vulnerable to arbitrary code execution caused by maliciously configured git email
Sources
Also known as GHSA-4vp2-6q8c-pvq2, MINI-7jrw-xrv3-pcw9, MINI-ch3q-w3rc-2w9r.