UNIX Symbolic Link (Symlink) Following Affecting @anthropic-ai/claude-code package, versions <2.1.64
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published24 Apr 2026
- disclosed21 Apr 2026
- creditUnknown
Introduced: 21 Apr 2026
NewCVE-2026-39861 (opens in a new tab)How to fix?
Upgrade @anthropic-ai/claude-code to version 2.1.64 or higher.
Overview
@anthropic-ai/claude-code is an Use Claude, Anthropic's AI assistant, right from your terminal. Claude can understand your codebase, edit files, run terminal commands, and handle entire workflows for you.
Affected versions of this package are vulnerable to UNIX Symbolic Link (Symlink) Following. An attacker can cause arbitrary files to be written outside the intended workspace by leveraging symlink manipulation and prompt injection to execute code in a sandboxed context, which is then followed by an unsandboxed process writing to the symlink target.
Note:
This is only exploitable if an attacker can inject untrusted content into the context window to trigger sandboxed code execution via prompt injection.