SEPTEMBER 9, 2026
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Case File

CVE-2026-56743

MEDIUM · CVSS 5.4 EPSS 0.16% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-07-15 · Last synced 2026-08-14

CyberRota Analysis

AI-Generated

Kubernetes versions 1.19.0 to 1.19.4 are vulnerable due to a flaw in Cilium's handling of NetworkPolicy specifications, where CIDR-based ipBlock rules can inadvertently create a wildcard namespace allow rule when a custom clusterName is used. This misconfiguration allows unauthorized traffic from other workloads within the same namespace, potentially compromising network security. Organizations using affected Kubernetes versions with Cilium should prioritize upgrading to version 1.19.5 to mitigate this risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-56743
Severity
MEDIUM
CVSS
5.4
EPSS
0.16%
Kubernetes

Original NVD 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.

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