Vulnerability · Published Jun 29, 2026 · Assigned by GitHub_M
CVE-2026-46406Claude Code: Insecure Temporary File in /copy Command Enables Response Disclosure and Symlink-Based File Write
Medium 4.4
In plain English
A medium-severity information exposure in claude-code from anthropics. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @anthropic-ai/claude-code | 2.1.128 | GHSA-4vp2-6q8c-pvq2 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| anthropics | claude-code | >= 2.1.59, < 2.1.128 |
Weakness: CWE-59, CWE-200, CWE-377 · 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