ghsa-67c9-f6v2-qv86

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "<= 4.2.0",
        "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-67c9-f6v2-qv86/GHSA-67c9-f6v2-qv86.json"
      },
      "package": {
        "ecosystem": "NuGet",
        "name": "Steeltoe.Discovery.Consul",
        "purl": "pkg:nuget/Steeltoe.Discovery.Consul"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.0",
        "4.1.0",
        "4.2.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-81516"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-755"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-17T20:30:54Z",
    "nvd_published_at": "2026-09-17T16:17:46Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nSteeltoe's Consul discovery client parses the `secure` metadata field on each registered service instance using `bool.Parse`, which throws on any value other than `true` or `false`. A single service instance registered with a malformed `secure` value (for example `yes` or `1`) aborts construction of the entire instance list for that service, making the service undiscoverable. When `GetAllInstancesAsync` is used, one malformed instance in any service can abort enumeration across all services.\nThis is the same \"one malformed field aborts the whole batch\" availability class as [CVE-2026-50196](https://github.com/advisories/GHSA-j8ph-6fxj-g533), but affecting the Consul discovery client.\n\n## Impact\n\nAny principal that can register a service in the Consul catalog can trigger a service-discovery outage for all Steeltoe applications resolving that service. The outage affects all instances of the targeted service — not just the malformed one — and persists until the offending registration is removed.\n\n## Affected configuration\n\n- Application uses `ConsulDiscoveryClient` (any deployment).\n- The Consul catalog contains at least one service instance with a `secure` metadata value that is not `true` or `false`.\n- Mixed-platform environments where non-.NET clients register services with non-standard metadata values are more likely to encounter this condition.\n\n## Mitigations\n\nIf an immediate upgrade is not possible:\n\n- Audit the Consul catalog for service registrations with non-standard `secure` metadata values.\n- Restrict write access to the Consul service registration API to trusted services.",
  "id": "GHSA-67c9-f6v2-qv86",
  "modified": "2026-09-17T20:45:06.563253507Z",
  "published": "2026-09-17T20:30:54Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-67c9-f6v2-qv86"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81516"
    },
    {
      "type": "WEB",
      "url": "https://github.com/SteeltoeOSS/Steeltoe/commit/028569c4f4f0e9e393e3c22a4fa5d07987dd8673"
    },
    {
      "type": "WEB",
      "url": "https://github.com/SteeltoeOSS/Steeltoe/releases/tag/4.3.0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/SteeltoeOSS/security-advisories"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Steeltoe.Discovery.Consul: malformed 'secure' metadata aborts service instance lookup (DoS)"
}