Bug 2494423 (CVE-2026-46406)

Summary: CVE-2026-46406 @anthropic-ai/claude-code: Claude Code: Information disclosure and file overwrite via insecure temporary file in /copy command
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anpicker, hasun, jfula, jowilson, msignori, nyancey, ometelka, ptisnovs, sdawley, syedriko, xdharmai
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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.
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Description OSIDB Bzimport 2026-06-29 15:01:43 UTC 
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.