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Medium

Claude SDK for TypeScript has Insecure Default File Permissions in Local Filesystem Memory Tool

Type: advisorySources: OSV

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 0.91.1, the BetaLocalFilesystemMemoryTool in the Anthropic TypeScript SDK created memory files and directories using the Node.js default modes (0o666 for files, 0o777 for directories), leaving them world-readable on systems with a standard umask and world-writable in environments with a permissive umask such as many Docker base images. A local attacker on a shared host could read persisted agent state, and in containerized deployments could modify memory files to influence subsequent model behavior. This issue has been patched in version 0.91.1.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-41686
Confirmed fixed CVEs
Not specified
Updated in this feed
6 Nov 2026, 02:08 UTC · Revision 1

Source evidence

Claude SDK for TypeScript has Insecure Default File Permissions in Local Filesystem Memory Tool

core-osv · Original source

Published 4 May 2026, 18:41 UTC

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 0.91.1, the BetaLocalFilesystemMemoryTool in the Anthropic TypeScript SDK created memory files and directories using the Node.js default modes (0o666 for files, 0o777 for directories), leaving them world-readable on systems with a standard umask and world-writable in environments with a permissive umask such as many Docker base images. A local attacker on a shared host could read persisted agent state, and in containerized deployments could modify memory files to influence subsequent model behavior. This issue has been patched in version 0.91.1.

osv:CVE-2026-41686
Complete source record
{
  "id": "cdd125fe75ea63b30e667593f868ab08222750b79a58dcc2c96f27de02afabc5",
  "url": "https://osv.dev/vulnerability/CVE-2026-41686",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Claude SDK for TypeScript has Insecure Default File Permissions in Local Filesystem Memory Tool",
    "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 0.91.1, the BetaLocalFilesystemMemoryTool in the Anthropic TypeScript SDK created memory files and directories using the Node.js default modes (0o666 for files, 0o777 for directories), leaving them world-readable on systems with a standard umask and world-writable in environments with a permissive umask such as many Docker base images. A local attacker on a shared host could read persisted agent state, and in containerized deployments could modify memory files to influence subsequent model behavior. This issue has been patched in version 0.91.1.",
    "evidence": "osv:CVE-2026-41686",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-41686",
      "aliases": [
        "CVE-2026-41686",
        "GHSA-p7fg-763f-g4gf"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/anthropics/anthropic-sdk-typescript",
              "type": "GIT",
              "events": [
                {
                  "introduced": "af66c809a5b59d6dc6e02e405b2c449fd9432e5e"
                },
                {
                  "fixed": "74ac150346ca92290b0fc57d9728e3841aa2dd54"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.79.0"
                      },
                      {
                        "fixed": "0.91.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:anthropic:claude_sdk_for_typescript:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.79.0"
                      },
                      {
                        "fixed": "0.91.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "sdk-v0.80.0",
            "sdk-v0.91.0",
            "bedrock-sdk-v0.29.0",
            "sdk-v0.90.0",
            "sdk-v0.89.0",
            "vertex-sdk-v0.16.0",
            "sdk-v0.88.0",
            "sdk-v0.87.0",
            "sdk-v0.86.1",
            "bedrock-sdk-v0.28.1",
            "sdk-v0.86.0",
            "aws-sdk-v0.2.5",
            "sdk-v0.85.0",
            "bedrock-sdk-v0.28.0",
            "sdk-v0.84.0",
            "vertex-sdk-v0.15.0",
            "sdk-v0.83.0",
            "sdk-v0.82.0",
            "bedrock-sdk-v0.27.0",
            "aws-sdk-v0.2.0",
            "sdk-v0.81.0",
            "sdk-v0.79.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-41686.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.177062755Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41686.json",
        "https://github.com/anthropics/anthropic-sdk-typescript/security/advisories/GHSA-p7fg-763f-g4gf",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-41686"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-732"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41686.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-41686",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514145,
  "published_at": "2026-05-04T18:41:40.183+00:00"
}