Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6

{
  "id": "cd2b9e8e1f0cb11a374c4940e74dd7c0bc67f6622cf9f8a9f3a90037dcd0fff6",
  "url": "https://osv.dev/vulnerability/CVE-2026-101087",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6",
    "summary": "Nezha versions 2.0.10 through 2.3.2 use a restricted HTTP client to validate user-configurable notification and DDNS webhook URLs, but the denylist did not cover IPv6 transition ranges — specifically the 6to4 prefix 2002::/16 and the local-use IPv4/IPv6 translation prefix 64:ff9b:1::/48. Because such addresses satisfy Go's netip.Addr.IsGlobalUnicast check, the URL validator accepted them. An authenticated user able to configure a webhook may be able to cause the dashboard to issue requests to an otherwise restricted IPv6 endpoint, but only where the dashboard's network provides unusual or non-standards-compliant routing for these transition ranges; no direct path to an IPv4 metadata, loopback, or private-network HTTP request has been demonstrated. The issue is fixed in version 2.3.3 (commit d1fcde8e), which blocks both prefixes.",
    "evidence": "osv:CVE-2026-101087",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-101087",
      "aliases": [
        "CVE-2026-101087",
        "GHSA-jr2j-7hvh-h4q9"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nezhahq/nezha",
              "type": "GIT",
              "events": [
                {
                  "introduced": "43624792a3ddcf11e8cc5fcd4538fa28cae36fc8"
                },
                {
                  "fixed": "71d43c6a6e2c57784b1f744787bb6ee3475f3cbb"
                },
                {
                  "fixed": "d1fcde8e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "2.0.10"
                      },
                      {
                        "fixed": "2.3.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "d1fcde8e"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101087.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.365492768Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101087.json",
        "https://github.com/nezhahq/nezha/security/advisories/GHSA-jr2j-7hvh-h4q9",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-101087",
        "https://www.vulncheck.com/advisories/nezha-2.0.10-through-2.3.2-ssrf-denylist-bypass-ipv6",
        "https://github.com/nezhahq/nezha/commit/d1fcde8e"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-918"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101087.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-101087",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491000,
  "published_at": "2026-09-27T20:49:58.749+00:00"
}