Local File Access Vulnerability in Anthropic Python SDK Affecting Claude API
CVE-2026-34450

4.8MEDIUM

Key Information:

Vendor

Anthropics

Status
Anthropic-sdk-python
Vendor
CVE Published:
31 March 2026

What is CVE-2026-34450?

The Anthropic Python SDK for accessing the Claude API has a vulnerability in its local filesystem memory tool that creates memory files with overly permissive permissions (mode 0o666). This flaw allows local attackers on shared hosts to read sensitive persisted agent state. In Docker containerized environments, malicious actors could modify these memory files, potentially altering the behavior of the model in subsequent operations. This issue affected both synchronous and asynchronous implementations of the memory tool and has been addressed in version 0.87.0.

Affected Version(s)

anthropic-sdk-python >= 0.86.0, < 0.87.0

References

https://github.com/anthropics/anthropic-sdk-python/securi...
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https://github.com/anthropics/anthropic-sdk-python/commit...
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https://github.com/anthropics/anthropic-sdk-python/releas...
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CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.