Vulnerability in Anthropic Claude Sdk For Python
CVE-2026-34450
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 local filesystem memory tool in the Anthropic Python SDK created memory files with mode 0o666, leaving them world-readable on systems with a standard umask and world-writable in environments with a permissive umask such as many Docker base images. A local attacker on a shared host could read persisted agent state, and in containerized deployments could modify memory files to influence subsequent model behavior. Both the synchronous and asynchronous memory tool implementations were affected. This issue has been patched in version 0.87.0.
EPSS: 0.001 (2.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/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-2026-34450?
- CVE-2026-34450 is a medium-severity vulnerability in Anthropic Claude Sdk For Python, classified under Incorrect Default Permissions. CVSS score: 4.4/10. Published 2026-03-31.
- How severe is CVE-2026-34450?
- Medium severity. CVSS v3 base score is 4.4 out of 10.