How severe is CVE-2020-5866?

CVE-2020-5866 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-5866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5866?

CVE-2020-5866 primarily affects F5 Nginx Controller. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-5866?

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

When was CVE-2020-5866 published?

CVE-2020-5866 was published on 2020-04-23 and last updated on 2026-06-17.

CVE-2020-5866

CVE-2020-5866 is a medium-severity vulnerability in F5 Nginx Controller with a CVSS 3.x base score of 5.5. 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: F5 Nginx Controller
Published: 2020-04-23
Last modified: 2026-06-17

Description

In versions of NGINX Controller prior to 3.3.0, the helper.sh script, which is used optionally in NGINX Controller to change settings, uses sensitive items as command-line arguments.

Frequently asked questions

What is CVE-2020-5866?: In versions of NGINX Controller prior to 3.3.0, the helper.sh script, which is used optionally in NGINX Controller to change settings, uses sensitive items as command-line arguments.
How severe is CVE-2020-5866?: CVE-2020-5866 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-5866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5866?: CVE-2020-5866 primarily affects F5 Nginx Controller. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-5866?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-5866 published?: CVE-2020-5866 was published on 2020-04-23 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:f5:nginx_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:f5:nginx_controller:1.0.1:*:*:*:*:*:*:*

More vulnerabilities in F5 Nginx Controller

CVE-2020-27730 — Critical (CVSS 9.8): In versions 3.0.0-3.9.0, 2.0.0-2.9.0, and 1.0.1, the NGINX Controller Agent does not use absolute paths when calling…
CVE-2020-5901 — Critical (CVSS 9.6): In NGINX Controller 3.3.0-3.4.0, undisclosed API endpoints may allow for a reflected Cross Site Scripting (XSS) attack.…
CVE-2020-5900 — High (CVSS 8.8): In versions 3.0.0-3.4.0, 2.0.0-2.9.0, and 1.0.1, there is insufficient cross-site request forgery (CSRF) protections…
CVE-2020-5863 — High (CVSS 8.6): In NGINX Controller versions prior to 3.2.0, an unauthenticated attacker with network access to the Controller API can…
CVE-2020-5894 — High (CVSS 8.1): On versions 3.0.0-3.3.0, the NGINX Controller webserver does not invalidate the server-side session token after users…
CVE-2020-5867 — High (CVSS 8.1): In versions prior to 3.3.0, the NGINX Controller Agent installer script 'install.sh' uses HTTP instead of HTTPS to…

All CVEs affecting F5 Nginx Controller →

Other CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities

CVE-2026-27604 — Critical (CVSS 10.0): FOSSBilling is a free, open-source billing and client management system. Starting in version 0.5.4 and prior to version…
CVE-2026-40965 — Critical (CVSS 10.0): Cloud Foundry UAA versions v76.12.0 through v78.12.0 are vulnerable to a private key exposure. The server contains a…
CVE-2026-42826 — Critical (CVSS 10.0): Exposure of sensitive information to an unauthorized actor in Azure DevOps allows an unauthorized attacker to disclose…
CVE-2025-29270 — Critical (CVSS 10.0): Incorrect access control in the realtime.cgi endpoint of Deep Sea Electronics devices DSE855 v1.1.0 to v1.1.26 allows…
CVE-2025-61481 — Critical (CVSS 10.0): An issue in MikroTik RouterOS v.7.14.2 and SwOS v.2.18 exposes the WebFig management interface over cleartext HTTP by…
CVE-2025-53624 — Critical (CVSS 10.0): The Docusaurus gists plugin adds a page to your Docusaurus instance, displaying all public gists of a GitHub user.…

Browse all CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities →