CVE-2026-46406
Description
A flaw was found in Claude Code. The /copy command created responses in a predictable, world-readable temporary file without proper isolation or symlink protection. This allowed a local unprivileged user to read sensitive information from a privileged user's Claude response, potentially containing secrets or credentials. Additionally, an attacker could exploit this by planting a symlink to overwrite an arbitrary file with the response text.
Statement
Red Hat rates this Moderate with a CVSS score of 6.8, higher than NIST's 6.1. The difference is in the confidentiality and integrity metrics.
Claude Code responses might contain secrets, API keys, credentials, and code, which is why Red Hat scores confidentiality as High rather than Low. On integrity, the symlink attack lets an unprivileged user redirect the write to any file the privileged process can touch — SSH authorized_keys, shell configs, application credentials. That can translate directly to privilege escalation, and Red Hat scores accordingly.
Exploitation requires a local account on the same system as the privileged user, who must also run the /copy command. The only Red Hat product shipping a vulnerable version is OpenShift Lightspeed (ships 2.1.123). Red Hat Dev Spaces ships 2.1.138 and is not affected.
Mitigation
Update Claude Code to version 2.1.128 or later, which uses randomized, UID-isolated temporary file paths with symlink protection. If updating is not immediately possible, avoid using the /copy command on multi-user systems where untrusted local users have access to /tmp.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.8 | 6.1 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | Low | N/A |
| Integrity Impact | High | Low | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Access Control
Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism
An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.
Other
Technical Impact: Execute Unauthorized Code or Commands
Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.
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