CVE-2023-34242
LowCVSS 3.4Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
Cilium, a networking, observability, and security solution, prior to version 1.13.4 had a vulnerability that allowed unintended access to secrets and services across namespaces when Gateway API was enabled. The lack of namespace checks when creating ReferenceGrant allowed attackers to use secrets that should not be visible to them.
Risk Assessment
The organization may be exposed to unauthorized access to sensitive data and services, potentially leading to serious security incidents. Attackers could exploit this vulnerability to communicate with services they should not have access to.
Recommendation
It is recommended to update Cilium to version 1.13.4 or later. Alternatively, restrict the creation of ReferenceGrant resources to admin users using Kubernetes RBAC.
Other vulnerabilities in Cilium
See all- CVE-2026-41520High
Cilium, a networking, observability, and security solution, prior to versions 1.17.15, 1.18.9, and 1.19.3, could output sensitive data when the cilium-bugtool was run against deployments with WireGuard encryption enabled.
- CVE-2026-49445Critical
In Cilium prior to versions 1.17.14, 1.18.8, and 1.19.2, when L7 functionality is enabled, the embedded or standalone Envoy instance creates a world-accessible admin.sock on cluster nodes. This allows a local attacker to access Envoy admin endpoints, expose TLS secrets, disrupt cluster traffic, or terminate Envoy.
- CVE-2026-56743Medium
A vulnerability in Cilium from version 1.19.0 to 1.19.4 causes standard Kubernetes NetworkPolicy specifications using CIDR-based ipBlock rules without pod or namespace selectors to erroneously generate a wildcard namespace allow rule when Cilium is configured with a custom clusterName.
- CVE-2026-56742Medium
A vulnerability in Cilium allows users with permissions to create or update namespaced HTTPRoutes to mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant authorization mechanism. Gateway API functionality is disabled by default.
- CVE-2026-53935Medium
A vulnerability in Cilium allows users with the ability to create CiliumLocalRedirectPolicies to hijack traffic to Services in any namespace by specifying arbitrary ClusterIPs via addressMatcher. Deleting such a policy can also corrupt Cilium internal service state and stop service translation for the affected Service.
Original NVD description (English source)
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to version 1.13.4, when Gateway API is enabled in Cilium, the absence of a check on the namespace in which a ReferenceGrant is created could result in Cilium unintentionally gaining visibility of secrets (including certificates) and services across namespaces. An attacker on an affected cluster can leverage this issue to use cluster secrets that should not be visible to them, or communicate with services that they should not have access to. Gateway API functionality is disabled by default. This vulnerability is fixed in Cilium release 1.13.4. As a workaround, restrict the creation of `ReferenceGrant` resources to admin users by using Kubernetes RBAC.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS