CVE-2023-39347
Cilium NetworkPolicy bypass via pod labels
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. An attacker with the ability to update pod labels can cause Cilium to apply incorrect network policies. This issue arises due to the fact that on pod update, Cilium incorrectly uses user-provided pod labels to select the policies which apply to the workload in question. This can affect Cilium network policies that use the namespace, service account or cluster constructs to restrict traffic, Cilium clusterwide network policies that use Cilium namespace labels to select the Pod and Kubernetes network policies. Non-existent construct names can be provided, which bypass all network policies applicable to the construct. For example, providing a pod with a non-existent namespace as the value of the `io.kubernetes.pod.namespace` label results in none of the namespaced CiliumNetworkPolicies applying to the pod in question. This attack requires the attacker to have Kubernetes API Server access, as described in the Cilium Threat Model. This issue has been resolved in: Cilium versions 1.14.2, 1.13.7, and 1.12.14. Users are advised to upgrade. As a workaround an admission webhook can be used to prevent pod label updates to the `k8s:io.kubernetes.pod.namespace` and `io.cilium.k8s.policy.*` keys.
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 12 months later
· 12 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.6 | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H |
| NVDNVD · Modified | 3.1 | Critical9.0 | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.57% · top 53% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.6.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/cilium/ciliumGHSA-gj2r-phwg-6rww (opens in a new tab)
References (2)
- https://github.com/cilium/cilium/security/advisories/GHSA-gj2r-phwg-6rww (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://docs.cilium.io/en/latest/security/threat-model/#kubernetes-api-server-attacker (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-gj2r-phwg-6rww (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-39347)Record last updated .