Medium severity · published Jun 29, 2026
CVE-2026-46406
Claude Code: Insecure Temporary File in /copy Command Enables Response Disclosure and Symlink-Based File Write
6.1
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CL
claude-code · anthropics
>= 2.1.59, < 2.1.128 · source: vendor
CC
Claude Code · Anthropic
2.1.58 before 2.1.128 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-46406
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-46406
Vendor Advisory
https://github.com/anthropics/claude-code/security/advisories/GHSA-4vp2-6q8c-pvq2
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