CVE catalog

CVE-2021-25736

kubernetes: CVE-2021-25736

Severity: Medium · CVSS 6.3CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
Published: May 10, 2021, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.92% · Oct 25, 2026

Kube-proxy on Windows can unintentionally forward traffic to local processes listening on the same port (“spec.ports[*].port”) as a LoadBalancer Service when the LoadBalancer controller does not set the “status.loadBalancer.ingress[].ip” field. Clusters where the LoadBalancer controller sets the “status.loadBalancer.ingress[].ip” field are unaffected.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	kubernetes	sid	`1.36.4+ds-1`	not affected
Debian	kubernetes	forky	`1.36.4+ds-1`	not affected
Debian	kubernetes	trixie	`1.32.3+ds-2`	not affected
Debian	kubernetes	bookworm	`1.20.5+really1.20.2-1.1+deb12u1`	not affected

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	kubernetes	source	sid	`Not affected`	unimportant	Not reported	Not reported
Debian	kubernetes	source	forky	`Not affected`	unimportant	Not reported	Not reported
Debian	kubernetes	source	trixie	`Not affected`	unimportant	Not reported	Not reported
Debian	kubernetes	source	bookworm	`Not affected`	unimportant	Not reported	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[kubernetes-client]Not affected
Source package: [kubernetes]
Details (2)
- 1.20.5+really1.20.2-1.1+deb12u1 · amd64 · bookworm
  Not affected
  dsa · kubernetes · debian · bookworm
- 1.20.5+really1.20.2-1.1+deb12u1 · arm64 · bookworm
  Not affected
  dsa · kubernetes · debian · bookworm

Observed: Oct 23, 2026, 5:55:10 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]