Claude SDK for TypeScript has 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
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.
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-typescript | 0.79.0 to before 0.91.1 | 0.91.1 | Patch available | CNA |
| — | @anthropic-ai/sdk (npm) | 0.79.0 to before 0.91.1 | 0.91.1 | Patch available | GHSA-p7fg-763f-g4gf |
- anthropic-sdk-typescript Vendoranthropics Affected 0.79.0 to before 0.91.1 Fixed in 0.91.1 Patch available CNA
- @anthropic-ai/sdk (npm) Vendor— Affected 0.79.0 to before 0.91.1 Fixed in 0.91.1 Patch available GHSA-p7fg-763f-g4gf
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:anthropic:claude_sdk_for_typescript:*:*:*:*:*:*:*:* | 0.79.0 to before 0.91.1 | Vulnerable | anthropics |
- cpe:2.3:a:anthropic:claude_sdk_for_typescript:*:*:*:*:*:*:*:* Versions 0.79.0 to before 0.91.1 Vulnerable ·anthropics
Remediation
- Fix · CNA anthropic-sdk-typescript (anthropics) Fixed in 0.91.1
- Fix · GHSA-p7fg-763f-g4gf @anthropic-ai/sdk (npm) Fixed in 0.91.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-41686
- 2026-10-03 Alias added: GHSA-p7fg-763f-g4gf
References
More anthropics Claude Sdk For Typescript vulnerabilities
- TI-2026-26716 Claude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories CVSS 4.0MEDIUM 6.3
Sources
- CVE-2026-41686 · CVE Program
- CVE-2026-41686 · NVD
- FIRST EPSS
- GHSA-p7fg-763f-g4gf · 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