CVE-2026-56743

Description

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.

Weakness classification

• security-advisories@github.com: CWE-863

Primary references

• security-advisories@github.com — Patch
• security-advisories@github.com — Patch
• security-advisories@github.com — Patch
• security-advisories@github.com — Patch
• security-advisories@github.com — Release Notes
• security-advisories@github.com — Vendor Advisory