Claude Code <2.1.251: Unsandboxed Edit Overwrites Files via Symlink (macOS)
CVE-2026-88968 Published on November 3, 2026
Claude Code: TOCTOU Race in Edit Tool Allows File Writes Outside the Workspace
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.
Vulnerability Analysis
CVE-2026-88968 is exploitable with network access. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Types
What is an insecure temporary file Vulnerability?
The software attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
CVE-2026-88968 has been classified to as an insecure temporary file vulnerability or weakness.
What is a TOCTTOU Vulnerability?
The software checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the software to perform invalid actions when the resource is in an unexpected state. This weakness can be security-relevant when an attacker can influence the state of the resource between check and use. This can happen with shared resources such as files, memory, or even variables in multithreaded programs.
CVE-2026-88968 has been classified to as a TOCTTOU vulnerability or weakness.
Products Associated with CVE-2026-88968
Want to know whenever a new CVE is published for Anthropic Claude Code? stack.watch will email you.
