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.
CVE-2026-56743
MEDIUMPre-NVD 5.45.4
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 5.4 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
5.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 5.4Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.4
- EG Score
- 5.4(low)
- EPSS
- —
- KEV
- Not listed
Published
July 15, 2026
Last Modified
July 15, 2026
Advisory Details (6)
Auto-updated Jul 16, 2026Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available
Cilium may unexpectedly allow ingress traffic from the local namespace when a Kubernetes NetworkPolicy is configured with an ipBlock match · Advisory · cilium/cilium · GitHub
https://github.com/cilium/cilium/security/advisories/GHSA-fm8w-2m5w-9j7rgithub_release Patch Available
1.19.5
Patch available: cilium/cilium v1.19.5
https://github.com/cilium/cilium/releases/tag/v1.19.5github_pr
[v1.19] fix: Fix wildcard namespace bypass for selectorless ipBlock rules
Fix merged in cilium/cilium PR #46456 on 2026-06-10 — awaiting tagged release
https://github.com/cilium/cilium/pull/46456github_pr
fix: Fix wildcard namespace bypass for selectorless ipBlock rules
Fix merged in cilium/cilium PR #46305 on 2026-06-09 — awaiting tagged release
https://github.com/cilium/cilium/pull/46305github_commit
commit bacea640404c (cilium/cilium)
Fix landed in cilium/cilium commit bacea640404c — awaiting tagged release
https://github.com/cilium/cilium/commit/bacea640404c0805c23515353dc1681c5bf35171github_commit
commit 1c84ae3b58a7 (cilium/cilium)
Fix landed in cilium/cilium commit 1c84ae3b58a7 — awaiting tagged release
https://github.com/cilium/cilium/commit/1c84ae3b58a7cd54f7ee355e6c524c82f620eae8Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-15 19:45 UTCEG score recompute
- 2026-07-15 19:44 UTCMITRE cvelistV5first tracked
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Same CWE
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Frequently asked(4)
What is CVE-2026-56743?
CVE-2026-56743 is a medium vulnerability published on July 15, 2026. 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…
When was CVE-2026-56743 disclosed?
CVE-2026-56743 was first published in the National Vulnerability Database on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-56743?
CVE-2026-56743 has a CVSS v3 base score of 5.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-56743?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56743, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-56743
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