CVE intelligence and bounded remediation
CVE-2026-56743 — Cilium is a networking, observability, and security solution
Cilium is a networking, observability, and security solution. From 1.19.0 to 1.19.4, standard Kubernetes NetworkPolicy specifications using CIDR-based ipBlock rules without pod or namespace selectors erroneously generate a wildcard namespace allow rule when Cilium is configured with a custom clusterName rather than the default any value. The parser incorrectly instantiates a pod selector on selectorless peer definitions, allowing traffic from other workloads in the same namespace as the subject of the policy. This issue is fixed in version 1.19.5.
- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Published
- 2026-07-15
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-863
Affected products
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Matched remediation archetype
Authorization bypass, IDOR, and cross-tenant access
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Check exposure
- Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
- Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
- Use synthetic fixtures to compare intended access matrices without accessing another user's real data.
Remediate safely
- Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
- Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
- Add deny-by-default policy tests for horizontal and vertical access across every affected transport.
Authoritative sources
Complete CVE record and remediation plan
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