---
id: CVE-2026-34451
title: >-
  Claude SDK for TypeScript provides access to the Claude API from server-side
  TypeScript or JavaScript applications
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 …
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-22
  - CWE-41
vendor: anthropic
product: claude_sdk_for_typescript
affected:
  - 'claude_sdk_for_typescript >= 0.79.0, < 0.81.0'
patched:
  - claude_sdk_for_typescript 0.81.0
published: '2026-03-31'
updated: '2026-07-24'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-34451'
references:
  - url: >-
      https://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9
    label: security-advisories@github.com
  - url: >-
      https://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0
    label: security-advisories@github.com
  - url: >-
      https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4c
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00349
epssPercentile: 0.28582
ingestedAt: '2026-07-25T21:03:58.058Z'
---

## Overview

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.

## Affected

- `claude_sdk_for_typescript >= 0.79.0, < 0.81.0`

## Remediation

Upgrade past the affected range:

- `claude_sdk_for_typescript 0.81.0`