CVE-2026-34451: Claude SDK for TypeScript Memory Tool Path Validation Allows Vulnerability

MODERATE
Advisory Identifier: GHSA-5474-4w2j-mq4c
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CVSS 5.4
CWE-41 CWE-22
Published
Advisory Summary

CVE-2026-34451 is a MODERATE (CVSS 5.4) memory tool path validation allows vulnerability (CWE-41: Improper Resolution of Path Equivalence) affecting Claude SDK for TypeScript libraries in the npm ecosystem. The issue involves memory tool path validation allows sandbox escape to sibling directories. Remediation is available by upgrading affected packages to version 0.81.0.

CVE-2026-34451 at a Glance

CVE Identifier CVE-2026-34451
GHSA Identifier GHSA-5474-4w2j-mq4c
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-41: Improper Resolution of Path Equivalence
Affected Product Claude SDK for TypeScript
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-34451

To remediate this vulnerability, upgrade all affected Claude SDK for TypeScript dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@anthropic-ai/sdk fixed: 0.81.0 
npm install @anthropic-ai/sdk@0.81.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls @anthropic-ai/sdk

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-34451, inspect your project dependencies using npm:

npm ls @anthropic-ai/sdk

Analyze the terminal output to locate any version of Claude SDK for TypeScript in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.81.0), your application is affected.

Note: The npm ls @anthropic-ai/sdk command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-41: Improper Resolution of Path Equivalence, where the product is vulnerable to file system contents disclosure through path equivalence. path equivalence involves the use of special characters in file and directory names. the associated manipulations are intended to generate multiple names for the same object. In Claude SDK for TypeScript, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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!

CVE-2026-34451 Affected Claude SDK for TypeScript Versions

1 component(s)
Fixed Versions:
0.81.0
Product / Package Ecosystem Affected Versions Fixed Version
@anthropic-ai/sdk
npm/@anthropic-ai/sdk
npm
≥ 0.79.0
< 0.81.0
0.81.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4c
NVD — CVE-2026-34451 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34451
Security Fix Commit FIX COMMIT
https://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9
Claude SDK for TypeScript Source Repository REPOSITORY
https://github.com/anthropics/anthropic-sdk-typescript
Claude SDK for TypeScript Release RELEASE
https://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0

Frequently Asked Questions

What is CVE-2026-34451?
CVE-2026-34451 is a security vulnerability in Claude SDK for TypeScript involving Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories under CWE-41: Improper Resolution of Path Equivalence.
Which Claude SDK for TypeScript versions are affected?
Affected versions include releases prior to 0.81.0 across affected packages: @anthropic-ai/sdk.
What version fixes CVE-2026-34451?
Upgrading to 0.81.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @anthropic-ai/sdk affected?
Yes, @anthropic-ai/sdk is affected in releases prior to 0.81.0. Upgrade your dependency to 0.81.0 or later.
What is the CVSS score of CVE-2026-34451?
CVE-2026-34451 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-34451?
CVE-2026-34451 is classified under CWE-41: Improper Resolution of Path Equivalence (The product is vulnerable to file system contents disclosure through path equivalence. Path equivalence involves the use of special characters in file and directory names. The associated manipulations are intended to generate multiple names for the same object.).
How can I check npm dependencies for CVE-2026-34451?
Run the dependency tree command: 'npm ls @anthropic-ai/sdk'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5474-4w2j-mq4c",
  "modified" : "2026-04-24T20:59:12Z",
  "published" : "2026-04-01T21:16:49Z",
  "aliases" : [ "CVE-2026-34451" ],
  "summary" : "Claude SDK for TypeScript: Memory Tool Path Validation Allows Sandbox Escape to Sibling Directories",
  "details" : "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.\n\nUsers on the affected versions are advised to update to the latest version.\n\nClaude SDK for TypeScript thanks [hackerone.com/nicksim](https://hackerone.com/nicksim) for reporting this issue!",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@anthropic-ai/sdk"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.79.0"
      }, {
        "fixed" : "0.81.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-5474-4w2j-mq4c"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34451"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/anthropics/anthropic-sdk-typescript/commit/0ac69b3438ee9c96b21a7d3c39c07b7cdb6995d9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/anthropics/anthropic-sdk-typescript"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/anthropics/anthropic-sdk-typescript/releases/tag/sdk-v0.81.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22", "CWE-41" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-01T21:16:49Z",
    "nvd_published_at" : "2026-03-31T22:16:20Z"
  }
}