Security advisory for Claude Code

Advisory overview

Claude Code is an agentic coding tool. Prior to 2.1.251, the Edit tool validates a target using pathname and symlink resolution that is not bound to the underlying directory inode or file descriptor. On macOS, attacker-controlled code running in the Bash sandbox can atomically replace an in-workspace parent directory with a symlink after validation, causing the unsandboxed Edit implementation to overwrite a user-writable file outside the workspace. Exploitation requires attacker-controlled code to run inside the sandbox, such as from a malicious repository or dependency script. This issue is fixed in version 2.1.251.

Related references

• https://github.com/anthropics/claude-code/releases/tag/v2.1.251
• https://github.com/anthropics/claude-code/security/advisories/GHSA-5xjx-9qx6-jcrv