How severe is CVE-2020-8559?

CVE-2020-8559 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-8559 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8559?

CVE-2020-8559 affects Kubernetes. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-8559?

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

When was CVE-2020-8559 published?

CVE-2020-8559 was published on 2020-07-22 and last updated on 2026-06-17.

CVE-2020-8559

CVE-2020-8559 is a medium-severity vulnerability in Kubernetes with a CVSS 3.x base score of 6.4. 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-601.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
CVSS v2: 6.0
EPSS exploit prediction: 6% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-601
Affected product: Kubernetes
Published: 2020-07-22
Last modified: 2026-06-17

Description

The Kubernetes kube-apiserver in versions v1.6-v1.15, and versions prior to v1.16.13, v1.17.9 and v1.18.6 are vulnerable to an unvalidated redirect on proxied upgrade requests that could allow an attacker to escalate privileges from a node compromise to a full cluster compromise.

Frequently asked questions

What is CVE-2020-8559?: The Kubernetes kube-apiserver in versions v1.6-v1.15, and versions prior to v1.16.13, v1.17.9 and v1.18.6 are vulnerable to an unvalidated redirect on proxied upgrade requests that could allow an attacker to escalate privileges from a node compromise to a full cluster compromise.
How severe is CVE-2020-8559?: CVE-2020-8559 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-8559 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8559?: CVE-2020-8559 affects Kubernetes. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-8559?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-8559 published?: CVE-2020-8559 was published on 2020-07-22 and last updated on 2026-06-17.

References

Affected products (1)

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

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