CVE-2026-56743

medium

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.

References

https://github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7r

https://github.com/cilium/cilium/releases/tag/v1.19.5

https://github.com/cilium/cilium/pull/46456

https://github.com/cilium/cilium/pull/46305

https://github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171

https://github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8

Details

Source: Mitre, NVD

Published: 2026-07-15

Updated: 2026-07-16

Risk Information

CVSS v2

Base Score: 4.1

Vector: CVSS2#AV:A/AC:L/Au:S/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.4

Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00158