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CWE-250Weakness · CWE-250

CVE-2026-50566

CRITICAL · 9.9 CVSS v3.1 Published 2026-06-10
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In Fission versions prior to 1.24.0, tenants with RBAC permissions to create/update environments.fission.io can deploy containers with privileged mode, allowPrivilegeEscalation, or dangerous capabilities (e.g., CAP_SYS_ADMIN). These containers run under the executor's high-privilege service account in the function/builder namespace, enabling container escape to access host filesystems, networks, and potentially compromise the entire node or cluster.

MitigationUpgrade Fission to version 1.24.0 or later. Additionally, audit and restrict RBAC policies for environments.fission.io to prevent untrusted users from creating privileged containers, and enforce Pod Security Standards (PSS) or Pod Security Policies (PSP) to block privileged workloads.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Fission version
    Run 'helm list -n fission' or 'kubectl get crd fissions -o jsonpath="{.spec.version}"' or check the fission-controller deployment image tag
    Affected if Version is prior to 1.24.0
  2. Verify environments.fission.io CRD exists
    Run 'kubectl get crd environments.fission.io' to confirm Fission is installed
    Affected if CRD exists and Fission version is below 1.24.0
  3. Check RBAC permissions on environments.fission.io
    Run 'kubectl auth can-i create environments.fission.io' as the tenant user or inspect ClusterRoleBindings/RoleBindings containing 'environments' permissions
    Affected if User or service account has create/update permissions on environments.fission.io
  4. Inspect function namespace for privileged pods
    Run 'kubectl get pods -n <function-namespace> -o json' and check spec.containers[*].securityContext for 'privileged: true', 'allowPrivilegeEscalation: true', or 'capabilities.add' containing dangerous caps
    Affected if Any pod in function or builder namespaces has these security context settings
  5. Check executor service account privileges
    Run 'kubectl get serviceaccount -n fission-function executor' and review its ClusterRoleBindings with 'kubectl auth can-i --list --as=system:serviceaccount:fission-function:executor'
    Affected if Executor service account has elevated cluster permissions beyond what's minimal

You are affected if Fission version is prior to 1.24.0 AND any user has environments.fission.io RBAC permissions AND privileged containers exist in function/builder namespaces running under the executor service account.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch github.com →
Interim mitigation

Upgrade Fission to version 1.24.0 or later. Additionally, audit and restrict RBAC policies for environments.fission.io to prevent untrusted users from creating privileged containers, and enforce Pod Security Standards (PSS) or Pod Security Policies (PSP) to block privileged workloads.

Recommended fix High confidence

1.24.0

  1. Upgrade Fission to version 1.24.0 or later using your Kubernetes package manager or deployment method (e.g., helm upgrade for Helm-based installations)

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation5.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,220
Get the patch applied

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,152.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-50566 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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