{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.23.0"
      },
      "package": {
        "ecosystem": "Go",
        "name": "github.com/fission/fission"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.24.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50564"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-269",
      "CWE-284",
      "CWE-693"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-30T18:19:32Z",
    "nvd_published_at": "2026-06-10T18:17:12Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\nFission\u0027s `Environment` CRD exposes `spec.runtime.podSpec` and `spec.builder.podSpec`, which are merged into the Kubernetes pod specs for runtime and builder pods. The merge logic propagated `hostNetwork`, `hostPID`, `hostIPC`, container\n `privileged`, and `serviceAccountName` from the user-supplied podspec with no filtering, and `Environment.Validate` performed no security-relevant checks on these fields.\n\n### Details\n\nA namespace user with `create`/`update` on `environments.fission.io` could produce privileged, host-network, hostPID pods in the Fission function or builder namespace. Because the Helm chart created the `fission-function` and\n`fission-builder` namespaces with no `pod-security.kubernetes.io/enforce` labels, Kubernetes Pod Security Admission did not catch the escape either.\n\nFrom a host-network privileged pod with hostPID, the attacker could `nsenter` into the host, read cloud-metadata credentials, access the container-runtime socket, pivot to other namespaces, and fully compromise the node.\n\n### Impact\n\n`environments.fission.io` create/update RBAC is escalated to node compromise \u2014 host filesystem and network access on the scheduling node, and from there potential cluster-wide takeover.\n\n### Fix\n\nFixed in [#3391](https://github.com/fission/fission/pull/3391) and released in [v1.24.0](https://github.com/fission/fission/releases/tag/v1.24.0). Denylist at admission (the primary defence) plus belt-and-braces at the merge layer.\n\n**Admission denylist** (`pkg/apis/core/v1/podspec_safety.go::ValidatePodSpecSafety`), called from `Environment.Validate` for both `Runtime.PodSpec` and `Builder.PodSpec`:\n\n- pod-level: `HostNetwork`, `HostPID`, `HostIPC`, `ServiceAccountName` / `DeprecatedServiceAccount` override, hostPath volumes;\n- per-container: `SecurityContext.Privileged=true`, `SecurityContext.AllowPrivilegeEscalation=true`, dangerous capabilities (`SYS_ADMIN`, `NET_ADMIN`, `SYS_PTRACE`, `SYS_MODULE`, `DAC_READ_SEARCH`, `DAC_OVERRIDE`).\n\n**Update-bypass closed:** the `Environment` validating-webhook marker is extended from `verbs=create` to `verbs=create;update` (chart and envtest manifests aligned).\n\n**Merge-layer belt-and-braces** (`pkg/executor/util/merge.go`): even if admission is bypassed (`failurePolicy=Ignore` or stale pre-webhook objects), the denylisted pod-level fields are stripped and per-container dangerous settings are\nsanitized before the merge (with `SecurityContext` deep-copied first so cached informer objects are not mutated). Legitimate operator hardening via the chart\u0027s pod-level `securityContext` (fsGroup, runAsNonRoot, runAsUser) still flows\nthrough.\n\n### Behavioural change\n\nEnvironments that explicitly set any denylisted field are now rejected at admission. There is no legitimate Fission use case \u2014 these primitives exist for cluster operators, not Environment authors.\n\nThis is the same root cause and fix as GHSA-wmgg-3p4h-48x7.",
  "id": "GHSA-gx55-f84r-v3r7",
  "modified": "2026-06-30T18:19:32Z",
  "published": "2026-06-30T18:19:32Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/security/advisories/GHSA-gx55-f84r-v3r7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50564"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/pull/3391"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/commit/e484df8460bb4e8026e24210120602aa7f181f64"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/fission/fission"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/releases/tag/v1.24.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Fission Environment CRD podspec passthrough enables hostPID/hostNetwork/privileged pods, node escape"
}