How severe is CVE-2020-5901?

CVE-2020-5901 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-5901 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5901?

CVE-2020-5901 affects F5 Nginx Controller. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-5901?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-5901 published?

CVE-2020-5901 was published on 2020-07-01 and last updated on 2026-06-17.

CVE-2020-5901

CVE-2020-5901 is a critical-severity vulnerability in F5 Nginx Controller with a CVSS 3.x base score of 9.6. 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-79.

Key facts

Severity: Critical (CVSS 3.x base score 9.6)
CVSS v2: 9.3
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: F5 Nginx Controller
Published: 2020-07-01
Last modified: 2026-06-17

Description

In NGINX Controller 3.3.0-3.4.0, undisclosed API endpoints may allow for a reflected Cross Site Scripting (XSS) attack. If the victim user is logged in as admin this could result in a complete compromise of the system.

Frequently asked questions

What is CVE-2020-5901?: In NGINX Controller 3.3.0-3.4.0, undisclosed API endpoints may allow for a reflected Cross Site Scripting (XSS) attack. If the victim user is logged in as admin this could result in a complete compromise of the system.
How severe is CVE-2020-5901?: CVE-2020-5901 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-5901 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5901?: CVE-2020-5901 affects F5 Nginx Controller. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-5901?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-5901 published?: CVE-2020-5901 was published on 2020-07-01 and last updated on 2026-06-17.

References

https://support.f5.com/csp/article/K43520321

Affected products (1)

cpe:2.3:a:f5:nginx_controller:*:*:*:*:*:*:*:*

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