Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-101087",
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "dateUpdated": "2026-09-27T20:49:58.749Z",
    "dateReserved": "2026-09-27T20:29:07.432Z",
    "datePublished": "2026-09-27T20:49:58.749Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck",
        "dateUpdated": "2026-09-27T20:49:58.749Z"
      },
      "datePublic": "2026-08-11T00:00:00.000Z",
      "title": "Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6",
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "affected": [
        {
          "vendor": "nezhahq",
          "product": "nezha",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "2.0.10",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "2.3.3"
            },
            {
              "version": "2.3.3",
              "status": "unaffected",
              "versionType": "semver"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "Server-Side Request Forgery (SSRF)",
              "cweId": "CWE-918",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/nezhahq/nezha/security/advisories/GHSA-jr2j-7hvh-h4q9",
          "name": "GitHub Security Advisory (GHSA-jr2j-7hvh-h4q9)",
          "tags": [
            "vendor-advisory"
          ]
        },
        {
          "url": "https://github.com/nezhahq/nezha/commit/d1fcde8e",
          "name": "Patch Commit",
          "tags": [
            "patch"
          ]
        },
        {
          "url": "https://www.vulncheck.com/advisories/nezha-2.0.10-through-2.3.2-ssrf-denylist-bypass-ipv6",
          "name": "VulnCheck Advisory: Nezha 2.0.10 through 2.3.2 SSRF Denylist Bypass IPv6",
          "tags": [
            "third-party-advisory"
          ]
        }
      ],
      "metrics": [
        {
          "format": "CVSS"
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
            "attackVector": "NETWORK",
            "attackComplexity": "LOW",
            "privilegesRequired": "LOW",
            "userInteraction": "NONE",
            "scope": "UNCHANGED",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "availabilityImpact": "NONE",
            "baseScore": 4.3,
            "baseSeverity": "MEDIUM"
          }
        }
      ]
    }
  }
}