Claude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- 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 0.81.0, the local filesystem memory tool in the Anthropic TypeScript SDK validated model-supplied paths using a string prefix check that did not append a trailing path separator. A model steered by prompt injection could supply a crafted path that resolved to a sibling directory sharing the memory root's name as a prefix, allowing reads and writes outside the sandboxed memory directory. This issue has been patched in version 0.81.0.
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-typescript | 0.79.0 to before 0.81.0 | 0.81.0 | Patch available | CNA |
| — | @anthropic-ai/sdk (npm) | 0.79.0 to before 0.81.0 | 0.81.0 | Patch available | GHSA-5474-4w2j-mq4c |
- anthropic-sdk-typescript Vendoranthropics Affected 0.79.0 to before 0.81.0 Fixed in 0.81.0 Patch available CNA
- @anthropic-ai/sdk (npm) Vendor— Affected 0.79.0 to before 0.81.0 Fixed in 0.81.0 Patch available GHSA-5474-4w2j-mq4c
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:anthropic:claude_sdk_for_typescript:*:*:*:*:*:*:*:* | 0.79.0 to before 0.81.0 | Vulnerable | anthropics |
- cpe:2.3:a:anthropic:claude_sdk_for_typescript:*:*:*:*:*:*:*:* Versions 0.79.0 to before 0.81.0 Vulnerable ·anthropics
Remediation
- Fix · CNA anthropic-sdk-typescript (anthropics) Fixed in 0.81.0
- Fix · GHSA-5474-4w2j-mq4c @anthropic-ai/sdk (npm) Fixed in 0.81.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34451
- 2026-10-03 Alias added: GHSA-5474-4w2j-mq4c
References
Advisory 2
More anthropics Claude Sdk For Typescript vulnerabilities
- TI-2026-30203 Claude SDK for TypeScript has Insecure Default File Permissions in Local Filesystem Memory Tool CVSS 4.0MEDIUM 4.8
Sources
- CVE-2026-34451 · CVE Program
- CVE-2026-34451 · NVD
- FIRST EPSS
- GHSA-5474-4w2j-mq4c · 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