axios4go's Race Condition in Shared HTTP Client Allows Proxy Configuration Leak

{
  "id": "a77a39ce07d9f57a6fa6ed5590b4683bfa104e20bbe2c4728bd703fb9f19232e",
  "url": "https://osv.dev/vulnerability/CVE-2026-21697",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "axios4go's Race Condition in Shared HTTP Client Allows Proxy Configuration Leak",
    "summary": "axios4go is a Go HTTP client library. Prior to version 0.6.4, a race condition vulnerability exists in the shared HTTP client configuration. The global `defaultClient` is mutated during request execution without synchronization, directly modifying the shared `http.Client`'s `Transport`, `Timeout`, and `CheckRedirect` properties. Impacted applications include that that use axios4go with concurrent requests (multiple goroutines, `GetAsync`, `PostAsync`, etc.), those where different requests use different proxy configurations, and those that handle sensitive data (authentication credentials, tokens, API keys). Version 0.6.4 fixes this issue.",
    "evidence": "osv:CVE-2026-21697",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-21697",
      "aliases": [
        "CVE-2026-21697",
        "GHSA-cmj9-27wj-7x47"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/rezmoss/axios4go",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "bc21ffb4e5fa9a743c7dbfac4c72764f97921444"
                },
                {
                  "fixed": "b651604c64e66a115ab90cdab358b0181d74a842"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:rezmoss:axios4go:*:*:*:*:*:go:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.6.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b651604c64e66a115ab90cdab358b0181d74a842"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "bc21ffb4e5fa9a743c7dbfac4c72764f97921444"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.6.4"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.6.3",
            "v0.6.2",
            "v0.6.1",
            "v0.6.0",
            "v0.5.0",
            "v0.4.0",
            "v0.3.0",
            "v0.2.1",
            "v0.2.0",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21697.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.164965435Z",
      "provider": "osv",
      "references": [
        "https://github.com/rezmoss/axios4go/releases/tag/v0.6.4",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21697.json",
        "https://github.com/rezmoss/axios4go/security/advisories/GHSA-cmj9-27wj-7x47",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-21697",
        "https://github.com/rezmoss/axios4go/commit/b651604c64e66a115ab90cdab358b0181d74a842"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-362"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21697.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-21697",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507478,
  "published_at": "2026-01-07T22:29:57.393+00:00"
}