Claude SDK for Python: Memory Tool Path Validation Race Condition Allows Sandbox Escape
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- High · 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 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.
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-w828-4qhx-vxx3 |
- 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-w828-4qhx-vxx3
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-w828-4qhx-vxx3 anthropic (PyPI) Fixed in 0.87.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34452
- 2026-10-03 Alias added: GHSA-w828-4qhx-vxx3
References
Patch 1
Advisory 2
More anthropics Claude Sdk For Python vulnerabilities
- TI-2026-26715 Claude SDK for Python: Insecure Default File Permissions in Local Filesystem Memory Tool CVSS 4.0MEDIUM 4.8
Sources
- CVE-2026-34452 · CVE Program
- CVE-2026-34452 · NVD
- FIRST EPSS
- GHSA-w828-4qhx-vxx3 · 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