CVE-2026-56743
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…
Does this matter?
Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- EPSS
- 0.25% probability · 16th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Affected
- cilium/cilium
- Source
- security-advisories@github.com
References
- https://github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8Patch
- https://github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171Patch
- https://github.com/cilium/cilium/pull/46305Patch
- https://github.com/cilium/cilium/pull/46456Patch
- https://github.com/cilium/cilium/releases/tag/v1.19.5Release Notes
- https://github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7rVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.