GitHub Advisoryadvisory · PyPI

GHSA-q5f5-3gjm-7mfm Claude SDK for Python has Insecure Default File Permissions in Local Filesystem Memory Tool

MEDIUM Published 2026-04-01 Modified 2026-04-01 Official page ↗
Aliases
CVE-2026-34450
Ecosystem
PyPI
Packages
anthropic
Severity
Moderate
CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Weaknesses
CWE-276, CWE-732
Reviewed
2026-04-01

Affected packages

• PyPI anthropic: >= 0.86.0, < 0.87.0 → fixed in 0.87.0

Description

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. Users on the affected versions are advised to update to the latest version. Claude SDK for Python thanks `lucasfutures` on HackerOne for the report.

Related

Alias · CVE (1)

  • CVE-2026-34450 The Claude SDK for Python provides access to the Claude API from Python applications. vulnerability

Weakness · CWE (2)

  • CWE-276 Incorrect Default Permissions weakness
  • CWE-732 Incorrect Permission Assignment for Critical Resource weakness

References