Claude SDK for Python: Insecure Default File Permissions in Local Filesystem Memory Tool
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| anthropics | anthropic-sdk-python | 0.86.0 to before 0.87.0 | 0.87.0 | Patch available | CNA |
| — | anthropic (PyPI) | 0.86.0 to before 0.87.0 | 0.87.0 | Patch available | GHSA-q5f5-3gjm-7mfm |
- anthropic-sdk-python Vendoranthropics Affected 0.86.0 to before 0.87.0 Fixed in 0.87.0 Patch available CNA
- anthropic (PyPI) Vendor— Affected 0.86.0 to before 0.87.0 Fixed in 0.87.0 Patch available GHSA-q5f5-3gjm-7mfm
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:anthropic:claude_sdk_for_python:*:*:*:*:*:python:*:* | 0.86.0 to before 0.87.0 | Vulnerable | anthropics |
- cpe:2.3:a:anthropic:claude_sdk_for_python:*:*:*:*:*:python:*:* Versions 0.86.0 to before 0.87.0 Vulnerable ·anthropics
Remediation
- Fix · CNA anthropic-sdk-python (anthropics) Fixed in 0.87.0
- Fix · GHSA-q5f5-3gjm-7mfm anthropic (PyPI) Fixed in 0.87.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34450
- 2026-10-03 Alias added: GHSA-q5f5-3gjm-7mfm
References
Patch 1
Advisory 2
More anthropics Claude Sdk For Python vulnerabilities
- TI-2026-26717 Claude SDK for Python: Memory Tool Path Validation Race Condition Allows Sandbox Escape CVSS 4.0MEDIUM 5.8
Sources
- CVE-2026-34450 · CVE Program
- CVE-2026-34450 · NVD
- FIRST EPSS
- GHSA-q5f5-3gjm-7mfm · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences