Claude Code: Insecure Temporary File in /copy Command Enables Response Disclosure and Symlink-Based File Write
Summary
| CVE | CVE-2026-46406 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-29 15:16:41 UTC |
| Updated | 2026-06-30 17:30:26 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 4.4 MEDIUM from [email protected]
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/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
EPSS: 0.001490000 probability, percentile 0.044880000 (date 2026-07-04)
Problem Types: CWE-59 | CWE-200 | CWE-377 | CWE-59 CWE-59: Improper Link Resolution Before File Access ('Link Following') | CWE-200 CWE-200: Exposure of Sensitive Information to an Unauthorized Actor | CWE-377 CWE-377: Insecure Temporary File
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 4.4 | MEDIUM | 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/E:X/C... |
| 4.0 | CNA | DECLARED | 4.4 | MEDIUM | 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 |
| 3.1 | [email protected] | Primary | 6.1 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H |
CVSS v4.0 Breakdown
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/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
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Anthropic | Claude Code | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Anthropics | Claude-code | affected >= 2.1.59, < 2.1.128 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/anthropics/claude-code/security/advisories/GHSA-4vp2-6q8c-pvq2 | [email protected] | github.com | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |