GHSA-m23h-6mwm-39m8: Github.com/kong/kubernetes ingress controller/v3 Cross-namespace TLS Secret Exfiltration Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m23h-6mwm-39m8",
  "modified" : "2026-05-19T19:30:23Z",
  "published" : "2026-05-19T19:30:23Z",
  "aliases" : [ ],
  "summary" : "Kong Ingress Controller for Kubernetes (KIC): Cross-namespace TLS Secret Exfiltration in Gateways with GatewayClass missing `konghq.com/gatewayclass-unmanaged: 'true'` annotation",
  "details" : "## Summary\n\nA vulnerability in the Kong Ingress Controller (KIC) allows for the unauthorized exfiltration of TLS certificates and private keys across Kubernetes namespace boundaries. In \"managed\" mode (where the `GatewayClass` lacks an unmanaged annotation), the Gateway TLS translator skips critical status checks. This bypass allows the translator to fetch Secrets from any namespace KIC watches, even when a `ReferenceGrant` explicitly denies access or is missing.\n\nAn actor with RBAC permissions to create or modify Gateways in a low-privileged namespace can reference a Secret in a high-privileged namespace, causing KIC to \"leak\" that Secret's sensitive private key material into the Kong dataplane configuration.\n\n## Am I affected?\n\nYou are affected if all of these hold:\n1. You are using Kong Ingress Controller with the **Gateway API**.\n2. Your `GatewayClass` is operating in **managed mode** (default behavior, no unmanaged annotation).\n3. KIC is configured to **watch multiple namespaces** (multi-tenant environment).\n4. Users have RBAC permissions to `create` or `update` `gateways.gateway.networking.k8s.io` in their own namespaces.\n\nYou are not affected if any of this:\n- You only use KIC for `Ingress` resources (not Gateway API).\n- Your `GatewayClass` uses the `konghq.com/gateway-unmanaged` annotation.\n- KIC is restricted via RBAC or configuration to only watch a single namespace.\n- You have strictly limited Gateway creation/modification permissions to trusted cluster administrators only.\n\n## Mitigation\n\n1. **Add unmanaged gateway annotation**: add the `konghq.com/gateway-unmanaged` annotation to your `GatewayClass`\n\n### Additional best practicies\n\n1. **Restrict Gateway RBAC**: Limit the ability to create or modify Gateway resources to high-trust administrative users until a patch is applied.\n2. **Namespace Isolation**: If possible, limit the namespaces KIC is permitted to watch using the `WATCH_NAMESPACE` environment variable or specific RBAC RoleBindings.\n\n## Fix\n\nThe fix mandates `ReferenceGrant` validation for all cross-namespace certificate references. By requiring a `Programmed: True` listener status, the translator now strictly authorizes external Secret access while maintaining default access for same-namespace certificates, effectively closing the exfiltration vector.\n\nFixed in [#7920](https://github.com/Kong/kubernetes-ingress-controller/pull/7920), with backports to supported release branches in [#7921](https://github.com/Kong/kubernetes-ingress-controller/pull/7921) and [#7922](https://github.com/Kong/kubernetes-ingress-controller/pull/7922).\n\nUpgrade to one of the following patched versions (or later):\n- **3.4.14**\n- **3.5.7**\n\n## CVSS\n\n`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P` = **5.6 Medium**",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/kong/kubernetes-ingress-controller/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.5.0"
      }, {
        "fixed" : "3.5.7"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.5.6"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/kong/kubernetes-ingress-controller/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.4.14"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.4.13"
    }
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/kong/kubernetes-ingress-controller/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.12.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/kong/kubernetes-ingress-controller"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.3.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Kong/kubernetes-ingress-controller/security/advisories/GHSA-m23h-6mwm-39m8"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kong/kubernetes-ingress-controller/pull/7920"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kong/kubernetes-ingress-controller/pull/7921"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kong/kubernetes-ingress-controller/pull/7922"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Kong/kubernetes-ingress-controller"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-19T19:30:23Z",
    "nvd_published_at" : null
  }
}