Medium
osv
ยท
GHSA-w828-4qhx-vxx3
Claude SDK for Python: Memory Tool Path Validation Race Condition Allows Sandbox Escape
Published Apr 1, 2026
CVSS 4.0
The async local filesystem memory tool in the Anthropic Python SDK validated that model-supplied paths resolved inside the sandboxed memory directory, but then returned the unresolved path for subsequent file operations. A local attacker able to write to the memory directory could retarget a symlink between validation and use, causing reads or writes to escape the sandbox. The synchronous memory tool implementation was not affected.
Users on the affected versions are advised to update to the latest version.
Claude SDK for Python thanks [hackerone.com/kasthelord](https://hackerone.com/kasthelord) for reporting this issue!
Affected AI Products
anthropic