CVE-2026-41686 Claude SDK for TypeScript has Insecure Default File Permissions in Local Filesystem Memory Tool
Local attackers can read or modify agent memory files due to insecure default permissions in the Claude TypeScript SDK.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-41686?
CVE-2026-41686 is a medium-severity vulnerability in anthropics anthropic-sdk-typescript, published on 4 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Claude SDK for TypeScript provides access to the Claude API from server-side TypeScript or JavaScript applications. From version 0.79.0 to before version 0.91.1, the BetaLocalFilesystemMemoryTool in the Anthropic TypeScript SDK created memory files and directories using the Node.js default modes (0o666 for files, 0o777 for directories), 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. This issue has been patched in version 0.91.1.
Weakness: CWE-732
Which versions are affected by CVE-2026-41686?
2 open source packages ship an affected version, including @anthropic-ai/sdk. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@anthropic-ai/sdk npm | From 0.79.0 | 0.91.1 |
@anthropic-ai/sdk npm | From 0.79.0 | 0.91.1 |
Products include Anthropic Claude Sdk for Typescript.
How do I fix CVE-2026-41686?
Upgrade @anthropic-ai/sdk to 0.91.1 or later.
Is CVE-2026-41686 being exploited?
There is no known exploitation of CVE-2026-41686 in the wild and no public exploit code.
Other vulnerabilities in anthropics anthropic-sdk-typescript
Sources
Also known as GHSA-p7fg-763f-g4gf, MINI-6c97-m979-9qgf.