Vulnerability-Lookup

GHSA-8WCJ-MFRC-JX5Q

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

Summary

Fission builder pods auto-mount the fission-builder ServiceAccount token in the user-supplied builder container

Details

Summary

Fission builder pods were created with ServiceAccountName: fission-builder and no AutomountServiceAccountToken: false, so the kubelet auto-mounted the service-account token into every container in the pod — including the user-supplied builder image.

Details

The user controls the builder container image, command, and podspec through Environment.spec.builder.image / .container / .podspec. With the SA token auto-mounted at /var/run/secrets/kubernetes.io/serviceaccount/token inside that container, any code running there inherited the fission-builder identity. The fission-builder SA holds namespace-wide get on secrets and configmaps (pkg/utils/serviceaccount.go), so the user-controlled builder container could read every Secret in the builder namespace by name.

This is the buildermgr sibling of GHSA-85g2-pmrx-r49q (CVE-2026-46617), whose fix suppressed the SA-token automount on function runtime pods but did not cover the structurally identical primitive in pkg/buildermgr/envwatcher.go.

Impact

A subject with create/update on Environment CRDs in a namespace observed by the buildermgr could read every Secret and ConfigMap in the builder namespace via the auto-mounted fission-builder token.

Fix

Fixed in #3390 and released in v1.24.0. In createBuilderDeployment:

Set pod-level AutomountServiceAccountToken=false on the initial PodSpec and add the projected fetcher SA-token volume.
Re-clamp AutomountServiceAccountToken=false after every MergePodSpec call so a user-supplied podspec cannot restore the kubelet automount.
Mount the token via a projected volume on the fetcher sidecar only, so the legitimate build → archive-upload flow keeps its cluster API access.

Reuses the projected-volume helpers from pkg/executor/util/satoken.go introduced by the GHSA-85g2-pmrx-r49q fix.

Behavioural change

The user-supplied builder container no longer receives an auto-mounted SA token. The fetcher sidecar still gets its token via a projected volume.

Severity

4.9 (Medium)


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

Show details on source website

JSON

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{
  "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-2026-50565"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-250",
      "CWE-269",
      "CWE-538"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-30T18:20:03Z",
    "nvd_published_at": "2026-06-10T18:17:12Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nFission builder pods were created with `ServiceAccountName: fission-builder` and no `AutomountServiceAccountToken: false`, so the kubelet auto-mounted the service-account token into every container in the pod \u2014 including the\nuser-supplied builder image.\n\n### Details\n\nThe user controls the builder container image, command, and podspec through `Environment.spec.builder.image` / `.container` / `.podspec`. With the SA token auto-mounted at `/var/run/secrets/kubernetes.io/serviceaccount/token` inside that\n container, any code running there inherited the `fission-builder` identity. The `fission-builder` SA holds namespace-wide `get` on `secrets` and `configmaps` (`pkg/utils/serviceaccount.go`), so the user-controlled builder container\ncould read every Secret in the builder namespace by name.\n\nThis is the buildermgr sibling of GHSA-85g2-pmrx-r49q (CVE-2026-46617), whose fix suppressed the SA-token automount on function runtime pods but did not cover the structurally identical primitive in `pkg/buildermgr/envwatcher.go`.\n\n### Impact\n\nA subject with `create`/`update` on `Environment` CRDs in a namespace observed by the buildermgr could read every Secret and ConfigMap in the builder namespace via the auto-mounted `fission-builder` token.\n\n### Fix\n\nFixed in [#3390](https://github.com/fission/fission/pull/3390) and released in [v1.24.0](https://github.com/fission/fission/releases/tag/v1.24.0). In `createBuilderDeployment`:\n\n- Set pod-level `AutomountServiceAccountToken=false` on the initial PodSpec and add the projected fetcher SA-token volume.\n- Re-clamp `AutomountServiceAccountToken=false` after every `MergePodSpec` call so a user-supplied podspec cannot restore the kubelet automount.\n- Mount the token via a projected volume on the fetcher sidecar only, so the legitimate build \u2192 archive-upload flow keeps its cluster API access.\n\nReuses the projected-volume helpers from `pkg/executor/util/satoken.go` introduced by the GHSA-85g2-pmrx-r49q fix.\n\n### Behavioural change\n\nThe user-supplied builder container no longer receives an auto-mounted SA token. The fetcher sidecar still gets its token via a projected volume.",
  "id": "GHSA-8wcj-mfrc-jx5q",
  "modified": "2026-06-30T18:20:03Z",
  "published": "2026-06-30T18:20:03Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/security/advisories/GHSA-8wcj-mfrc-jx5q"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50565"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/pull/3390"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fission/fission/commit/8fa799417c77ce8a0189d9858bfe11ece29b84a6"
    },
    {
      "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:H/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Fission builder pods auto-mount the fission-builder ServiceAccount token in the user-supplied builder container"
}

CVE-2026-50565 (GCVE-0-2026-50565)

Vulnerability from cvelistv5 – Published: 2026-06-10 17:28 – Updated: 2026-06-10 18:42

Title

Fission builder pods auto-mount the fission-builder ServiceAccount token in the user-supplied builder container

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, Fission builder pods were created with ServiceAccountName: fission-builder and no AutomountServiceAccountToken: false, so the kubelet auto-mounted the service-account token into every container in the pod — including the user-supplied builder image. This issue has been patched in version 1.24.0.

Severity

4.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-10 18:38 UTC

CWE

CWE-250 - Execution with Unnecessary Privileges
CWE-269 - Improper Privilege Management
CWE-538 - Insertion of Sensitive Information into Externally-Accessible File or Directory

Assigner

GitHub_M mitre root Scorecard

References

3 references

URL	Tags
https://github.com/fission/fission/security/advis…	x_refsource_CONFIRM
https://github.com/fission/fission/pull/3390	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-2026-50565",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-10T18:38:05.730903Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-10T18:42:31.704Z",
          "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, Fission builder pods were created with ServiceAccountName: fission-builder and no AutomountServiceAccountToken: false, so the kubelet auto-mounted the service-account token into every container in the pod \u2014 including the user-supplied builder image. This issue has been patched in version 1.24.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N",
            "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"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-538",
              "description": "CWE-538: Insertion of Sensitive Information into Externally-Accessible File or Directory",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-10T17:28:27.457Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/fission/fission/security/advisories/GHSA-8wcj-mfrc-jx5q",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/fission/fission/security/advisories/GHSA-8wcj-mfrc-jx5q"
        },
        {
          "name": "https://github.com/fission/fission/pull/3390",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/fission/fission/pull/3390"
        },
        {
          "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-8wcj-mfrc-jx5q",
        "discovery": "UNKNOWN"
      },
      "title": "Fission builder pods auto-mount the fission-builder ServiceAccount token in the user-supplied builder container"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-50565",
    "datePublished": "2026-06-10T17:28:27.457Z",
    "dateReserved": "2026-06-04T21:34:34.426Z",
    "dateUpdated": "2026-06-10T18:42:31.704Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

GHSA-8WCJ-MFRC-JX5Q

Summary

Details

Impact

Fix

Behavioural change

CVE-2026-50565 (GCVE-0-2026-50565)

Tags

Sightings

Nomenclature

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