EUVD-2026-36100
GHSA-gx55-f84r-v3r7
Severity by source
AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Primary rating from NVD.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Lifecycle Timeline
4DescriptionNVD
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's 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 privileged, and serviceAccountName from the user-supplied podspec with no filtering, and Environment.Validate performed no security-relevant checks on these fields. This issue has been patched in version 1.24.0.
Articles & Coverage 2
AnalysisAI
Privilege escalation in Fission (Kubernetes-native serverless framework) prior to version 1.24.0 allows a tenant with Environment CRD write access to escape the container sandbox and reach node- or cluster-level privileges by setting unfiltered fields in spec.runtime.podSpec or spec.builder.podSpec. Because the fission-executor and fission-builder service accounts schedule pods on the tenant's behalf, attacker-controlled values for hostNetwork, hostPID, hostIPC, container privileged, and serviceAccountName are merged into pod specs without validation. No public exploit identified at time of analysis, but the patch's hardening scope (also closing GHSA-wmgg-3p4h-48x7 and GHSA-v455-mv2v-5g92) shows the issue is broader than a single field.
Technical ContextAI
Fission is an open-source serverless framework that runs user-defined functions as Kubernetes pods. The Environment CRD lets users supply a Kubernetes PodSpec template (spec.runtime.podSpec for the function runtime, spec.builder.podSpec for the build container) that Fission merges into the actual pod manifests created by the fission-executor and fission-builder controllers. The root cause is CWE-269 (Improper Privilege Management): the Environment.Validate webhook performed no security-relevant filtering, so privileged fields like hostNetwork, hostPID, hostIPC, container.securityContext.privileged, and serviceAccountName flowed through into the pod that the executor/builder service accounts create. Because those controller service accounts are authorized to create pods cluster-wide, any field crossing the sandbox boundary (host namespaces, hostPath volumes, dangerous capabilities, alternate ServiceAccount) effectively becomes a vehicle for the low-privilege tenant to reach node- or cluster-level state. The CPE cpe:2.3:a:fission:fission:*:*:*:*:*:*:*:* covers all versions up to the fix.
RemediationAI
Vendor-released patch: upgrade Fission to 1.24.0 or later (https://github.com/fission/fission/releases/tag/v1.24.0), which introduces ValidatePodSpecSafety in pkg/apis/core/v1/podspec_safety.go to reject hostNetwork, hostPID, hostIPC, serviceAccountName/DeprecatedServiceAccount overrides, hostPath volumes, container privileged, allowPrivilegeEscalation, and dangerous capabilities (SYS_ADMIN, NET_ADMIN, SYS_PTRACE, SYS_MODULE, DAC_READ_SEARCH, DAC_OVERRIDE) via the admission webhook on both CREATE and UPDATE; see PR https://github.com/fission/fission/pull/3391 and advisory https://github.com/fission/fission/security/advisories/GHSA-gx55-f84r-v3r7. Until the upgrade is rolled out, restrict who can create or update Environment (and Function) CRDs via Kubernetes RBAC so only trusted operators hold those rights - this directly removes the PR:L precondition but also blocks legitimate tenant self-service. As a layered control, deploy a cluster-wide policy engine (Kyverno, OPA/Gatekeeper, or Pod Security Admission set to restricted) to deny pods with hostNetwork/hostPID/hostIPC, privileged containers, hostPath volumes, or non-default ServiceAccount in the fission-function namespace; note this will also reject any legitimate function that genuinely needs those fields, so audit existing Environments first.
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View allVendor StatusVendor
SUSE
Severity: Critical| Product | Status |
|---|---|
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
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External POC / Exploit Code
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