CVE-2026-34450

Claude SDK for Python: Insecure Default File Permissions in Local Filesystem Memory Tool

MEDIUM
4.4
CVSS Score
Published: March 31, 2026 at 09:32 PM UTC
Updated: July 24, 2026 at 09:20 PM UTC
2 products affected across 2 vendorsClaude SDK for PythonClaude SDK for Python

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Severity
MEDIUM4.4
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.86.0 ≤ v < 0.87.0
Affected range stops below 0.87.0, so it looks safe — our inference, not a vendor statement
v < 0.87.0
Affected range stops below 0.87.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-276CWE-732

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