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PatchSiren cyber security CVE debrief

CVE-2026-50564 Fission CVE debrief

CVE-2026-50564 is a critical security vulnerability in Fission, an open-source, Kubernetes-native serverless framework. The issue allows for potential privilege escalation due to the Environment CRD exposing spec.runtime.podSpec and spec.builder.podSpec, which are merged into Kubernetes pod specs without adequate filtering or validation. This could enable an attacker to exploit the system by setting hostNetwork, hostPID, hostIPC, container privileged, and serviceAccountName fields. The vulnerability has been patched in version 1.24.0.

Vendor
Fission
Product
Fission
CVSS
CRITICAL 9.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-10
Original CVE updated
2026-06-10
Advisory published
2026-06-10
Advisory updated
2026-06-10

Who should care

Users of Fission, especially those who have not upgraded to version 1.24.0, should be aware of this vulnerability and take immediate action to mitigate potential risks.

Technical summary

The Environment CRD in Fission exposes spec.runtime.podSpec and spec.builder.podSpec, which are merged into Kubernetes pod specs for runtime and builder pods. Prior to version 1.24.0, the merge logic propagated sensitive fields such as hostNetwork, hostPID, hostIPC, container privileged, and serviceAccountName without filtering. Environment.Validate did not perform security-relevant checks on these fields, potentially allowing an attacker to escalate privileges.

Defensive priority

High

Recommended defensive actions

  • Upgrade to Fission version 1.24.0 or later to apply the patch.
  • Review and restrict user-supplied pod specs to prevent exploitation of sensitive fields.
  • Implement additional security measures, such as network policies and role-based access control, to limit potential damage.

Evidence notes

The CVE-2026-50564 issue has a CVSS score of 9.9 and is classified as CRITICAL. The vulnerability was published on 2026-06-10T18:17:12.740Z and modified on 2026-06-10T19:37:41.437Z.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50564 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50564

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-50564 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50564

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.