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

> Prompt injection allows attackers to escape the memory tool sandbox and read or write files in sibling directories via flawed path validation.

- **Severity:** Medium 6.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Mar 2026
- **Updated:** 1 Apr 2026
- **Also known as:** GHSA-5474-4w2j-mq4c, MINI-c7c2-44rc-8m8g

## What is CVE-2026-34451?

CVE-2026-34451 is a medium-severity path traversal vulnerability in anthropics anthropic-sdk-typescript, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, 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 0.81.0, 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.

Weakness: CWE-41 (Improper Resolution of Path Equivalence), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-34451?

2 open source packages ship an affected version, including @anthropic-ai/sdk. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@anthropic-ai/sdk` | npm | From 0.79.0 | 0.81.0 |
| `@anthropic-ai/sdk` | npm | From 0.79.0 | 0.81.0 |

Products: Anthropic Claude Sdk for Typescript.

## How do I fix CVE-2026-34451?

Upgrade @anthropic-ai/sdk to 0.81.0 or later.

## Is CVE-2026-34451 being exploited?

There is no known exploitation of CVE-2026-34451 in the wild and no public exploit code.

## Other vulnerabilities in anthropics anthropic-sdk-typescript

- [CVE-2026-41686](https://insights.sbomify.com/CVE-2026-41686/): Claude SDK for TypeScript has Insecure Default File Permissions in Local Filesystem Memory Tool (medium 4.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34451 and fix it if it is affected.

What it is: CVE-2026-34451 is a medium-severity path traversal vulnerability in anthropics anthropic-sdk-typescript, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34451 in the wild and no public exploit code.

Affected packages and fixed versions:
- @anthropic-ai/sdk (npm): affected from 0.79.0; fixed in 0.81.0
- @anthropic-ai/sdk (npm): affected from 0.79.0; fixed in 0.81.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34451/ (Markdown: https://insights.sbomify.com/CVE-2026-34451/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34451
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34451
- OSV: https://osv.dev/vulnerability/CVE-2026-34451

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34451/
Summaries are generated and may contain mistakes; the official description above is the record.