Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-35c7-w35f-xwgh

Kube-proxy may unintentionally forward traffic

CVSS 5.8 MediumEPSS 0.0092 · 60th percentile

Published by the GitHub Advisory Database at 30 Oct 2023, 03:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
k8s.io/kubernetesGo<1.21.01.21.0
Identifiers
GHSA-35c7-w35f-xwgh · CVE-2021-25736 · GO-2023-2159
Weakness (CWE)
CWE-114
Tags
Published
30 Oct 2023
Updated
10 Sept 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Kubernetes (k8s.io/kubernetes) versions before 1.21.0 are affected. On Windows, kube-proxy can forward traffic meant for a LoadBalancer Service to local processes listening on the same port when the LoadBalancer controller does not set the status.loadBalancer.ingress[].ip field. Upgrade to 1.21.0 or later. Clusters where the LoadBalancer controller sets that field are not affected.

Written 2 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
5.8 Medium 3.1 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:N/A:N CNA (kubernetes)
  • CISA KEV Not listed.
  • EPSS 0.0092, the 60th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:15 UTC First seen by agentprime
  2. 31 Oct 2026, 14:15 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.