nosurf vulnerable to CSRF due to non-functional same-origin request checks

{
  "id": "1e297388918647267d12ef429b825cdee64966d107aaeaedec5a36a258c13f11",
  "url": "https://osv.dev/vulnerability/CVE-2025-46721",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "nosurf vulnerable to CSRF due to non-functional same-origin request checks",
    "summary": "nosurf is cross-site request forgery (CSRF) protection middleware for Go. A vulnerability in versions prior to 1.2.0 allows an attacker who controls content on the target site, or on a subdomain of the target site (either via XSS, or otherwise) to bypass CSRF checks and issue requests on user's behalf. Due to misuse of the Go `net/http` library, nosurf categorizes all incoming requests as plain-text HTTP requests, in which case the `Referer` header is not checked to have the same origin as the target webpage. If the attacker has control over HTML contents on either the target website (e.g. `example.com`), or on a website hosted on a subdomain of the target (e.g. `attacker.example.com`), they will also be able to manipulate cookies set for the target website. By acquiring the secret CSRF token from the cookie, or overriding the cookie with a new token known to the attacker, `attacker.example.com` is able to craft cross-site requests to `example.com`. A patch for the issue was released in nosurf 1.2.0. In lieu of upgrading to a patched version of nosurf, users may additionally use another HTTP middleware to ensure that a non-safe HTTP request is coming from the same origin (e.g. by requiring a `Sec-Fetch-Site: same-origin` header in the request).",
    "evidence": "osv:CVE-2025-46721",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-46721",
      "aliases": [
        "CVE-2025-46721",
        "GHSA-w9hf-35q4-vcjw",
        "GO-2025-3683"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/justinas/nosurf",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ec9bb776d8e5ba9e906b6eb70428f4e7b009feee"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.2.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ec9bb776d8e5ba9e906b6eb70428f4e7b009feee"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ec9bb776d8e5ba9e906b6eb70428f4e7b009feee"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.2.0"
                  },
                  {
                    "cpe": "cpe:2.3:a:nosurf_project:nosurf:*:*:*:*:*:go:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.2.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.1.1",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-46721.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.522169725Z",
      "provider": "osv",
      "references": [
        "https://github.com/justinas/nosurf/releases/tag/v1.2.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/46xxx/CVE-2025-46721.json",
        "https://github.com/advisories/GHSA-rq77-p4h8-4crw",
        "https://github.com/justinas/nosurf/security/advisories/GHSA-w9hf-35q4-vcjw",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-46721",
        "https://github.com/justinas/nosurf/commit/ec9bb776d8e5ba9e906b6eb70428f4e7b009feee",
        "https://github.com/justinas/nosurf-cve-2025-46721"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-352"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/46xxx/CVE-2025-46721.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-46721",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 520256,
  "published_at": "2025-05-13T15:29:30.068+00:00"
}