What is CVE-2026-86831?

CVE-2026-86831 is a high-severity vulnerability in AWS Amazon-Vpc-Cni-K8s, classified under CWE-1289. CVSS score: 8.7/10. Published 2026-09-16.

How severe is CVE-2026-86831?

High severity. CVSS v3 base score is 8.7 out of 10.

Vulnerability in AWS Amazon-Vpc-Cni-K8s

CVE-2026-86831

Improper validation of pod identifier uniqueness in aws-network-policy-agent in Amazon EKS Network Policy Agent before v1.4.0 might allow an authenticated remote user to bypass NetworkPolicy enforcement on co-located pods in other namespaces via crafted pod and namespace names that produce pod identifier collisions. To remediate this issue, users should upgrade to Amazon EKS Network Policy Agent 1.4.0 or later and Amazon VPC CNI Managed Add-on v1.22.4 or later (which includes Network Policy Agent v1.4.0).

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

CWE-1289

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (release-notes, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (release-notes, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (release-notes)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (release-notes)

Frequently asked questions

What is CVE-2026-86831?: CVE-2026-86831 is a high-severity vulnerability in AWS Amazon-Vpc-Cni-K8s, classified under CWE-1289. CVSS score: 8.7/10. Published 2026-09-16.
How severe is CVE-2026-86831?: High severity. CVSS v3 base score is 8.7 out of 10.