{"id":"CVE-2026-56743","summary":"Cilium may unexpectedly allow ingress traffic from the local namespace when a Kubernetes NetworkPolicy is configured with an ipBlock match","details":"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.","aliases":["BIT-cilium-2026-56743","BIT-cilium-operator-2026-56743","BIT-hubble-relay-2026-56743","GHSA-fm8w-2m5w-9j7r"],"modified":"2026-07-20T08:41:21.459638942Z","published":"2026-07-15T19:15:30.924Z","database_specific":{"cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56743.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/cilium/cilium/releases/tag/v1.19.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56743.json"},{"type":"ADVISORY","url":"https://github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56743"},{"type":"FIX","url":"https://github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8"},{"type":"FIX","url":"https://github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171"},{"type":"FIX","url":"https://github.com/cilium/cilium/pull/46305"},{"type":"FIX","url":"https://github.com/cilium/cilium/pull/46456"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cilium/cilium","events":[{"introduced":"7c6667e1e707d7f39a4af3409c2a9ebea2917d32"},{"fixed":"20eaccfef029cb046d70219717fb6dbbdf27a59f"},{"fixed":"1c84ae3b58a7cd54f7ee355e6c524c82f620eae8"},{"fixed":"bacea640404c0805c23515353dc1681c5bf35171"}],"database_specific":{"extracted_events":[{"introduced":"1.19.0"},{"fixed":"1.19.5"}],"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:cilium:cilium:*:*:*:*:*:*:*:*"}}],"versions":["v1.19.4","1.19.4","v1.19.3","1.19.3","v1.19.2","1.19.2","v1.19.1","1.19.1","v1.19.0","1.19.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56743.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N"}]}