CVE-2026-34451
MEDIUM5.4EPSS 0.03%Claude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories
Published: 4/1/2026Modified: 5/5/2026
Also known as:GHSA-5474-4w2j-mq4c
Description
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. Users on the affected versions are advised to update to the latest version. Claude SDK for TypeScript thanks [hackerone.com/nicksim](https://hackerone.com/nicksim) for reporting this issue!
Affected packages (1)
- npm/@anthropic-ai/sdk>= 0.79.0, < 0.81.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
| osv | CVSS 3.1 | MEDIUM5.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N |
References (5)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-34451
- PATCHhttps://github.com/anthropics/anthropic-sdk-typescript
- WEBhttps://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9
- WEBhttps://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0
- WEBhttps://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4c