CVE-2026-33726 (GCVE-0-2026-33726)
Vulnerability from cvelistv5
Published
2026-03-27 00:23
Modified
2026-03-27 13:50
Severity ?
VLAI Severity ?
EPSS score ?
Summary
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.17.14, 1.18.8, and 1.19.2, Ingress Network Policies are not enforced for traffic from pods to L7 Services (Envoy, GAMMA) with a local backend on the same node, when Per-Endpoint Routing is enabled and BPF Host Routing is disabled. Per-Endpoint Routing is disabled by default, but is automatically enabled in deployments using cloud IPAM, including Cilium ENI on EKS (`eni.enabled`), AlibabaCloud ENI (`alibabacloud.enabled`), Azure IPAM (`azure.enabled`, but not AKS BYOCNI), and some GKE deployments (`gke.enabled`; managed offerings such as GKE Dataplane V2 may use different defaults). It is typically not enabled in tunneled deployments, and chaining deployments are not affected. In practice, Amazon EKS with Cilium ENI mode is likely the most common affected environment. Versions 1.17.14, 1.18.8, and 1.19.2 contain a patch. There is currently no officially verified or comprehensive workaround for this issue. The only option would be to disable per-endpoint routes, but this will likely cause disruptions to ongoing connections, and potential conflicts if running in cloud providers.
References
| URL | Tags | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||||||||||
Impacted products
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-33726",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-03-27T13:24:20.808024Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-03-27T13:50:24.672Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "cilium",
"vendor": "cilium",
"versions": [
{
"status": "affected",
"version": "\u003c 1.17.14"
},
{
"status": "affected",
"version": "\u003e= 1.18.0, \u003c 1.18.8"
},
{
"status": "affected",
"version": "\u003e= 1.19.0, \u003c 1.19.2"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.17.14, 1.18.8, and 1.19.2, Ingress Network Policies are not enforced for traffic from pods to L7 Services (Envoy, GAMMA) with a local backend on the same node, when Per-Endpoint Routing is enabled and BPF Host Routing is disabled. Per-Endpoint Routing is disabled by default, but is automatically enabled in deployments using cloud IPAM, including Cilium ENI on EKS (`eni.enabled`), AlibabaCloud ENI (`alibabacloud.enabled`), Azure IPAM (`azure.enabled`, but not AKS BYOCNI), and some GKE deployments (`gke.enabled`; managed offerings such as GKE Dataplane V2 may use different defaults). It is typically not enabled in tunneled deployments, and chaining deployments are not affected. In practice, Amazon EKS with Cilium ENI mode is likely the most common affected environment. Versions 1.17.14, 1.18.8, and 1.19.2 contain a patch. There is currently no officially verified or comprehensive workaround for this issue. The only option would be to disable per-endpoint routes, but this will likely cause disruptions to ongoing connections, and potential conflicts if running in cloud providers."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-284",
"description": "CWE-284: Improper Access Control",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-863",
"description": "CWE-863: Incorrect Authorization",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-03-27T00:23:21.795Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/cilium/cilium/security/advisories/GHSA-hxv8-4j4r-cqgv",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/cilium/cilium/security/advisories/GHSA-hxv8-4j4r-cqgv"
},
{
"name": "https://github.com/cilium/cilium/pull/44693",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/cilium/cilium/pull/44693"
},
{
"name": "https://docs.cilium.io/en/stable/network/concepts/routing/#routing",
"tags": [
"x_refsource_MISC"
],
"url": "https://docs.cilium.io/en/stable/network/concepts/routing/#routing"
},
{
"name": "https://docs.cilium.io/en/stable/network/kubernetes/policy/#network-policy",
"tags": [
"x_refsource_MISC"
],
"url": "https://docs.cilium.io/en/stable/network/kubernetes/policy/#network-policy"
},
{
"name": "https://docs.cilium.io/en/stable/network/servicemesh/l7-traffic-management",
"tags": [
"x_refsource_MISC"
],
"url": "https://docs.cilium.io/en/stable/network/servicemesh/l7-traffic-management"
},
{
"name": "https://docs.cilium.io/en/stable/operations/performance/tuning/#ebpf-host-routing",
"tags": [
"x_refsource_MISC"
],
"url": "https://docs.cilium.io/en/stable/operations/performance/tuning/#ebpf-host-routing"
}
],
"source": {
"advisory": "GHSA-hxv8-4j4r-cqgv",
"discovery": "UNKNOWN"
},
"title": "Cilium L7 proxy may bypass Kubernetes NetworkPolicy for same-node traffic"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-33726",
"datePublished": "2026-03-27T00:23:21.795Z",
"dateReserved": "2026-03-23T17:34:57.559Z",
"dateUpdated": "2026-03-27T13:50:24.672Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-33726\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-27T13:24:20.808024Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-27T13:24:24.487Z\"}}], \"cna\": {\"title\": \"Cilium L7 proxy may bypass Kubernetes NetworkPolicy for same-node traffic\", \"source\": {\"advisory\": \"GHSA-hxv8-4j4r-cqgv\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 5.4, \"attackVector\": \"ADJACENT_NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"cilium\", \"product\": \"cilium\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.17.14\"}, {\"status\": \"affected\", \"version\": \"\u003e= 1.18.0, \u003c 1.18.8\"}, {\"status\": \"affected\", \"version\": \"\u003e= 1.19.0, \u003c 1.19.2\"}]}], \"references\": [{\"url\": \"https://github.com/cilium/cilium/security/advisories/GHSA-hxv8-4j4r-cqgv\", \"name\": \"https://github.com/cilium/cilium/security/advisories/GHSA-hxv8-4j4r-cqgv\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/cilium/cilium/pull/44693\", \"name\": \"https://github.com/cilium/cilium/pull/44693\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://docs.cilium.io/en/stable/network/concepts/routing/#routing\", \"name\": \"https://docs.cilium.io/en/stable/network/concepts/routing/#routing\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://docs.cilium.io/en/stable/network/kubernetes/policy/#network-policy\", \"name\": \"https://docs.cilium.io/en/stable/network/kubernetes/policy/#network-policy\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://docs.cilium.io/en/stable/network/servicemesh/l7-traffic-management\", \"name\": \"https://docs.cilium.io/en/stable/network/servicemesh/l7-traffic-management\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://docs.cilium.io/en/stable/operations/performance/tuning/#ebpf-host-routing\", \"name\": \"https://docs.cilium.io/en/stable/operations/performance/tuning/#ebpf-host-routing\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.17.14, 1.18.8, and 1.19.2, Ingress Network Policies are not enforced for traffic from pods to L7 Services (Envoy, GAMMA) with a local backend on the same node, when Per-Endpoint Routing is enabled and BPF Host Routing is disabled. Per-Endpoint Routing is disabled by default, but is automatically enabled in deployments using cloud IPAM, including Cilium ENI on EKS (`eni.enabled`), AlibabaCloud ENI (`alibabacloud.enabled`), Azure IPAM (`azure.enabled`, but not AKS BYOCNI), and some GKE deployments (`gke.enabled`; managed offerings such as GKE Dataplane V2 may use different defaults). It is typically not enabled in tunneled deployments, and chaining deployments are not affected. In practice, Amazon EKS with Cilium ENI mode is likely the most common affected environment. Versions 1.17.14, 1.18.8, and 1.19.2 contain a patch. There is currently no officially verified or comprehensive workaround for this issue. The only option would be to disable per-endpoint routes, but this will likely cause disruptions to ongoing connections, and potential conflicts if running in cloud providers.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-284\", \"description\": \"CWE-284: Improper Access Control\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-863\", \"description\": \"CWE-863: Incorrect Authorization\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-03-27T00:23:21.795Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2026-33726\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-27T13:50:24.672Z\", \"dateReserved\": \"2026-03-23T17:34:57.559Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-03-27T00:23:21.795Z\", \"assignerShortName\": \"GitHub_M\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…