Medium severity5.4NVD Advisory· Published Jul 15, 2026· Updated Jul 17, 2026
CVE-2026-56743
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/cilium/ciliumGo | >= 1.19.0, < 1.19.5 | 1.19.5 |
Affected products
10- osv-coords8 versionspkg:apk/chainguard/kubescapepkg:apk/chainguard/kubescape-serverpkg:apk/chainguard/kubescape-server-downloaderpkg:apk/chainguard/kubescape-server-fips-downloaderpkg:apk/wolfi/kubescapepkg:bitnami/ciliumpkg:bitnami/cilium-operatorpkg:bitnami/hubble-relay
< 4.0.12-r13+ 7 more
- (no CPE)range: < 4.0.12-r13
- (no CPE)range: < 4.0.12-r12
- (no CPE)range: < 4.0.12-r12
- (no CPE)range: < 4.0.12-r11
- (no CPE)range: < 4.0.12-r13
- (no CPE)range: >= 1.19.0, < 1.19.5
- (no CPE)range: >= 1.19.0, < 1.19.5
- (no CPE)range: >= 1.19.0, < 1.19.5
Patches
Vulnerability mechanics
References
8- github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8nvdPatchWEB
- github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171nvdPatchWEB
- github.com/cilium/cilium/pull/46305nvdPatchWEB
- github.com/cilium/cilium/pull/46456nvdPatchWEB
- github.com/advisories/GHSA-fm8w-2m5w-9j7rghsaADVISORY
- github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7rnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-56743ghsaADVISORY
- github.com/cilium/cilium/releases/tag/v1.19.5nvdRelease NotesWEB
News mentions
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