CVE-2026-34451
mediumpriority · track · 22EPSS 0.003 · 28 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
- anthropic claude sdk for typescript0.79.0 → 0.81.0nvdUScpe:2.3:a:anthropic:claude_sdk_for_typescript:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-5474-4w2j-mq4cClaude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories2026-04-01ghsa · osvUS
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!
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (11)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-34451cnnvd
- https://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9cnnvd
- https://github.com/anthropics/anthropic-sdk-typescript/releasesPatchcnnvd
- https://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0cnnvd
- https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4ccnnvd
- https://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9enisa_euvd
- https://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0enisa_euvd
- https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4cenisa_euvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan