Vulnerability in Anthropic Claude Sdk For Python
CVE-2026-34452
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.
EPSS: 0.001 (3.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N.
Affected products
- Anthropic Claude_sdk_for_python
- Anthropics Anthropic-sdk-python — versions >= 0.86.0, < 0.87.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-34452?
- CVE-2026-34452 is a medium-severity vulnerability in Anthropic Claude Sdk For Python, classified under Improper Link Resolution Before File Access. CVSS score: 5.3/10. Published 2026-03-31.
- How severe is CVE-2026-34452?
- Medium severity. CVSS v3 base score is 5.3 out of 10.