How severe is CVE-2020-8558?

CVE-2020-8558 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-8558 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8558?

CVE-2020-8558 affects Kubernetes. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-8558?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-8558 published?

CVE-2020-8558 was published on 2020-07-27 and last updated on 2026-06-17.

CVE-2020-8558

CVE-2020-8558 is a medium-severity vulnerability in Kubernetes with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-420.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 5.8
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-420
Affected product: Kubernetes
Published: 2020-07-27
Last modified: 2026-06-17

Description

The Kubelet and kube-proxy components in versions 1.1.0-1.16.10, 1.17.0-1.17.6, and 1.18.0-1.18.3 were found to contain a security issue which allows adjacent hosts to reach TCP and UDP services bound to 127.0.0.1 running on the node or in the node's network namespace. Such a service is generally thought to be reachable only by other processes on the same host, but due to this defeect, could be reachable by other hosts on the same LAN as the node, or by containers running on the same node as the service.

Frequently asked questions

What is CVE-2020-8558?: The Kubelet and kube-proxy components in versions 1.1.0-1.16.10, 1.17.0-1.17.6, and 1.18.0-1.18.3 were found to contain a security issue which allows adjacent hosts to reach TCP and UDP services bound to 127.0.0.1 running on the node or in the node's network namespace. Such a service is generally thought to be reachable only by other processes on the same host, but due to this defeect, could be reachable by other hosts on the same LAN as the node, or by containers running on the same node as the service.
How severe is CVE-2020-8558?: CVE-2020-8558 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-8558 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8558?: CVE-2020-8558 affects Kubernetes. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-8558?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-8558 published?: CVE-2020-8558 was published on 2020-07-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*

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