Axios: CIDR-form NO_PROXY entries are ignored, causing proxy exclusion bypass for internal IP ranges

{
  "id": "655f524c3372b7bd711ac19c976aa57259913ad484ab56a7e93864c18bc7b190",
  "url": "https://osv.dev/vulnerability/CVE-2026-101899",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Axios: CIDR-form NO_PROXY entries are ignored, causing proxy exclusion bypass for internal IP ranges",
    "summary": "Axios is a promise-based HTTP client for the browser and Node.js. From 1.15.0 until 1.20.0, Axios shouldBypassProxy treats the NO_PROXY CIDR form as a textual hostname suffix instead of evaluating the network range. A request targets an address covered by a CIDR entry in NO_PROXY while a proxy is configured. The CIDR bypass rule is not matched, so the request is sent through the configured proxy. For plaintext HTTP, the proxy can observe and modify URLs, headers, and bodies; for HTTPS, it can observe connection metadata and CONNECT requests. This issue is fixed in version 1.20.0.",
    "evidence": "osv:CVE-2026-101899",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-101899",
      "aliases": [
        "CVE-2026-101899",
        "GHSA-44g4-m2mj-wpvx"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/axios/axios",
              "type": "GIT",
              "events": [
                {
                  "introduced": "772a4e54ecc4cc2421e2b746daff0aca10f359d7"
                },
                {
                  "fixed": "84a9f3b9a4f3244b8c8e818f557d64c7b964fb25"
                },
                {
                  "fixed": "d19040bda7a8be2f82c3c6e1a5bc03917daee39a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.15.0"
                      },
                      {
                        "fixed": "1.20.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "d19040bda7a8be2f82c3c6e1a5bc03917daee39a"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "84a9f3b9a4f3244b8c8e818f557d64c7b964fb25"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.20.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.19.0",
            "v1.18.1",
            "v1.18.0",
            "v1.17.0",
            "v1.16.1",
            "v1.16.0",
            "v1.15.2",
            "v1.15.1",
            "v1.15.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101899.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.159896340Z",
      "provider": "osv",
      "references": [
        "https://github.com/axios/axios/releases/tag/v1.20.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101899.json",
        "https://github.com/axios/axios/security/advisories/GHSA-44g4-m2mj-wpvx",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-101899",
        "https://github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a",
        "https://github.com/axios/axios/pull/11141"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-693"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101899.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-101899",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507779,
  "published_at": "2026-10-13T15:49:51.223+00:00"
}