Vulnerability-Lookup

GHSA-M63V-2G9W-2W6V

Vulnerability from github – Published: 2026-06-30 18:20 – Updated: 2026-06-30 18:20

Summary

Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation

Details

Summary

A follow-up bypass of the round-4 PodSpec hardening (GHSA-gx55-f84r-v3r7, GHSA-wmgg-3p4h-48x7, GHSA-v455-mv2v-5g92). Those advisories validate and sanitize the PodSpec (spec.runtime.podSpec / spec.builder.podSpec / function.spec.podSpec), but the Environment CRD also exposes spec.runtime.container and spec.builder.container — a standalone Container merged into the runtime/builder pod whose SecurityContext bypassed both layers.

Details

Admission-layer gap. Environment.Validate() calls ValidatePodSpecSafety() on Runtime.PodSpec and Builder.PodSpec only. That function takes a *PodSpec, so it never inspects the standalone Runtime.Container.SecurityContext or Builder.Container.SecurityContext.

Merge-layer gap. sanitizeContainerSecurityContext() ran only inside MergePodSpec(). The container field is merged via MergeContainer(), which did not sanitize. With only Runtime.Container set and Runtime.PodSpec nil, MergePodSpec is never invoked, so the sanitizer never ran.

Affected merge sites: poolmgr (gp_deployment.go), newdeploy (newdeploy.go), and buildermgr (envwatcher.go).

Proof of concept

apiVersion: fission.io/v1
kind: Environment
metadata:
  name: priv-escape-test
  namespace: default
spec:
  version: 3
  runtime:
    image: "ghcr.io/fission/python-env:latest"
    container:
      name: priv-escape-test
      securityContext:
        privileged: true
  poolsize: 1

The admission webhook accepts this Environment and the resulting pool pod runs with privileged: true. Equivalent bypasses: allowPrivilegeEscalation: true, capabilities.add: ["SYS_ADMIN"], capabilities.add: ["NET_ADMIN","SYS_PTRACE"]. The same attack applies to Builder.Container.

Impact

A tenant with environments.fission.io create/update RBAC can run privileged / allowPrivilegeEscalation / dangerous-capability containers in the Fission function or builder namespace, scheduled under the executor's high-privilege service account — enabling container-sandbox escape, host filesystem and network access, and potential node- and cluster-level compromise. Identical blast radius to GHSA-gx55-f84r-v3r7.

Fix

Fixed in #3406 and released in v1.24.0.

Admission layer (primary defence): a new ValidateContainerSafety in pkg/apis/core/v1/podspec_safety.go applies the per-container SecurityContext denylist (privileged, allowPrivilegeEscalation, dangerous capabilities) to a standalone container, and is called from Environment.Validate() for Runtime.Container and Builder.Container.
Merge layer (defence in depth): sanitizeContainerSecurityContext() is now invoked inside MergeContainer() itself, covering all three executor/builder call sites.

Workarounds

Restrict Environment create/update RBAC to trusted administrators.
Deploy a Kyverno / OPA Gatekeeper policy rejecting dangerous Container SecurityContext on Environment CRDs.
Label the function/builder namespaces with pod-security.kubernetes.io/enforce: restricted.

References

GHSA-gx55-f84r-v3r7, GHSA-wmgg-3p4h-48x7, GHSA-v455-mv2v-5g92 — the round-4 PodSpec fixes this advisory bypasses (#3391, e484df84).

Severity

9.9 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "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-2026-50566"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-250",
      "CWE-269"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-30T18:20:39Z",
    "nvd_published_at": "2026-06-10T18:17:13Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\nA follow-up bypass of the round-4 PodSpec hardening (GHSA-gx55-f84r-v3r7, GHSA-wmgg-3p4h-48x7, GHSA-v455-mv2v-5g92). Those advisories validate and sanitize the `PodSpec` (`spec.runtime.podSpec` / `spec.builder.podSpec` /\n`function.spec.podSpec`), but the Environment CRD also exposes `spec.runtime.container` and `spec.builder.container` \u2014 a standalone `Container` merged into the runtime/builder pod whose `SecurityContext` bypassed both layers.\n\n### Details\n\n**Admission-layer gap.** `Environment.Validate()` calls `ValidatePodSpecSafety()` on `Runtime.PodSpec` and `Builder.PodSpec` only. That function takes a `*PodSpec`, so it never inspects the standalone `Runtime.Container.SecurityContext`\nor `Builder.Container.SecurityContext`.\n\n**Merge-layer gap.** `sanitizeContainerSecurityContext()` ran only inside `MergePodSpec()`. The container field is merged via `MergeContainer()`, which did not sanitize. With only `Runtime.Container` set and `Runtime.PodSpec` nil,\n`MergePodSpec` is never invoked, so the sanitizer never ran.\n\nAffected merge sites: poolmgr (`gp_deployment.go`), newdeploy (`newdeploy.go`), and buildermgr (`envwatcher.go`).\n\n#### Proof of concept\n\n```yaml\napiVersion: fission.io/v1\nkind: Environment\nmetadata:\n  name: priv-escape-test\n  namespace: default\nspec:\n  version: 3\n  runtime:\n    image: \"ghcr.io/fission/python-env:latest\"\n    container:\n      name: priv-escape-test\n      securityContext:\n        privileged: true\n  poolsize: 1\n```\n\nThe admission webhook accepts this Environment and the resulting pool pod runs with `privileged: true`. Equivalent bypasses: `allowPrivilegeEscalation: true`, `capabilities.add: [\"SYS_ADMIN\"]`, `capabilities.add:\n[\"NET_ADMIN\",\"SYS_PTRACE\"]`. The same attack applies to `Builder.Container`.\n\n### Impact\n\nA tenant with `environments.fission.io` create/update RBAC can run `privileged` / `allowPrivilegeEscalation` / dangerous-capability containers in the Fission function or builder namespace, scheduled under the executor\u0027s high-privilege\nservice account \u2014 enabling container-sandbox escape, host filesystem and network access, and potential node- and cluster-level compromise. Identical blast radius to GHSA-gx55-f84r-v3r7.\n\n### Fix\n\nFixed in [#3406](https://github.com/fission/fission/pull/3406) and released in [v1.24.0](https://github.com/fission/fission/releases/tag/v1.24.0).\n\n- **Admission layer (primary defence):** a new `ValidateContainerSafety` in `pkg/apis/core/v1/podspec_safety.go` applies the per-container SecurityContext denylist (`privileged`, `allowPrivilegeEscalation`, dangerous capabilities) to a\nstandalone container, and is called from `Environment.Validate()` for `Runtime.Container` and `Builder.Container`.\n- **Merge layer (defence in depth):** `sanitizeContainerSecurityContext()` is now invoked inside `MergeContainer()` itself, covering all three executor/builder call sites.\n\n### Workarounds\n\n- Restrict Environment create/update RBAC to trusted administrators.\n- Deploy a Kyverno / OPA Gatekeeper policy rejecting dangerous Container SecurityContext on Environment CRDs.\n- Label the function/builder namespaces with `pod-security.kubernetes.io/enforce: restricted`.\n\n### References\n\n- GHSA-gx55-f84r-v3r7, GHSA-wmgg-3p4h-48x7, GHSA-v455-mv2v-5g92 \u2014 the round-4 PodSpec fixes this advisory bypasses ([#3391](https://github.com/fission/fission/pull/3391), `e484df84`).",
  "id": "GHSA-m63v-2g9w-2w6v",
  "modified": "2026-06-30T18:20:39Z",
  "published": "2026-06-30T18:20:39Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/security/advisories/GHSA-m63v-2g9w-2w6v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50566"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/pull/3406"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/commit/695d3e97e3a20463ab7c8c081843e69e65e952e5"
    },
    {
      "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 Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation"
}

CVE-2026-50566 (GCVE-0-2026-50566)

Vulnerability from cvelistv5 – Published: 2026-06-10 17:29 – Updated: 2026-06-12 12:44

Title

Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation

Summary

Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.24.0, a tenant with environments.fission.io create/update RBAC can run privileged / allowPrivilegeEscalation / dangerous-capability containers in the Fission function or builder namespace, scheduled under the executor's high-privilege service account — enabling container-sandbox escape, host filesystem and network access, and potential node- and cluster-level compromise. This issue has been patched in version 1.24.0.

Severity

9.9 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-250 - Execution with Unnecessary Privileges
CWE-269 - Improper Privilege Management

Assigner

GitHub_M

References

3 references

URL	Tags
https://github.com/fission/fission/security/advis…	x_refsource_CONFIRM
https://github.com/fission/fission/pull/3406	x_refsource_MISC
https://github.com/fission/fission/releases/tag/v1.24.0	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
fission	fission	Affected: < 1.24.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-50566",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-12T03:55:23.879271Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-12T12:44:18.213Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "fission",
          "vendor": "fission",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.24.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.24.0, a tenant with environments.fission.io create/update RBAC can run privileged / allowPrivilegeEscalation / dangerous-capability containers in the Fission function or builder namespace, scheduled under the executor\u0027s high-privilege service account \u2014 enabling container-sandbox escape, host filesystem and network access, and potential node- and cluster-level compromise. This issue has been patched in version 1.24.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.9,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-250",
              "description": "CWE-250: Execution with Unnecessary Privileges",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-269",
              "description": "CWE-269: Improper Privilege Management",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-10T17:29:35.349Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/fission/fission/security/advisories/GHSA-m63v-2g9w-2w6v",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/fission/fission/security/advisories/GHSA-m63v-2g9w-2w6v"
        },
        {
          "name": "https://github.com/fission/fission/pull/3406",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/fission/fission/pull/3406"
        },
        {
          "name": "https://github.com/fission/fission/releases/tag/v1.24.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/fission/fission/releases/tag/v1.24.0"
        }
      ],
      "source": {
        "advisory": "GHSA-m63v-2g9w-2w6v",
        "discovery": "UNKNOWN"
      },
      "title": "Fission: Environment Runtime.Container and Builder.Container SecurityContext bypass allows privileged pod creation"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-50566",
    "datePublished": "2026-06-10T17:29:35.349Z",
    "dateReserved": "2026-06-04T21:34:34.426Z",
    "dateUpdated": "2026-06-12T12:44:18.213Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-M63V-2G9W-2W6V

Summary

Details

Proof of concept

Impact

Fix

Workarounds

References

CVE-2026-50566 (GCVE-0-2026-50566)

Tags

Sightings

Nomenclature