CVE-2026-34452
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
Claude SDK for Python versions 0.86.0 to before 0.87.0 has a vulnerability in the async local filesystem memory tool. Path validation is performed but the unresolved path is returned, allowing a local attacker to use symlinks to escape the sandbox.
Risk Assessment
A local attacker can read or write files outside the memory directory, leading to privilege escalation or data leakage.
Recommendation
Update Claude SDK to version 0.87.0 or later which contains the fix.
Original NVD description (English source)
The Claude SDK for Python provides access to the Claude API from Python applications. From version 0.86.0 to before version 0.87.0, 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. This issue has been patched in version 0.87.0.