CVE-2026-34452 Details
Description
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.
A vulnerability in the Claude SDK for Python, specifically in versions 0.86.0 prior to 0.87.0, allows for sandbox escape by manipulating symlinks. The issue arises in the asynchronous local filesystem memory tool, which incorrectly handled path validation. While the tool validated that model-supplied paths were within the sandboxed memory directory, it then returned the unresolved path for subsequent file operations. This flaw created a time-of-check-to-time-of-use (TOCTOU) race condition. A local attacker with write access to the memory directory could exploit this by retargeting a symlink between the validation and the actual file operation, causing reads or writes to escape the sandbox. The synchronous memory tool was not affected by this vulnerability.
Users are advised to update the Anthropic Claude SDK for Python to version 0.87.0 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 3, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-367 | Time-of-check Time-of-use (TOCTOU) Race Condition | [email protected] |
| CWE-59 | Improper Link Resolution Before File Access ('Link Following') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| anthropic claude sdk for python | >= 0.86.0, < 0.87.0 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 20, 2026 | Initial Analysis | [email protected] |
| Mar 31, 2026 | New CVE Received | [email protected] |