How severe is CVE-2020-28693?

CVE-2020-28693 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-28693 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-28693?

CVE-2020-28693 affects Horizontcms Project Horizontcms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-28693?

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

When was CVE-2020-28693 published?

CVE-2020-28693 was published on 2020-11-16 and last updated on 2026-06-17.

CVE-2020-28693

CVE-2020-28693 is a high-severity vulnerability in Horizontcms Project Horizontcms with a CVSS 3.x base score of 8.8. 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-434.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 2% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Horizontcms Project Horizontcms
Published: 2020-11-16
Last modified: 2026-06-17

Description

An unrestricted file upload issue in HorizontCMS 1.0.0-beta allows an authenticated remote attacker to upload PHP code through a zip file by uploading a theme, and executing the PHP file via an HTTP GET request to /themes/<php_file_name>

Frequently asked questions

What is CVE-2020-28693?: An unrestricted file upload issue in HorizontCMS 1.0.0-beta allows an authenticated remote attacker to upload PHP code through a zip file by uploading a theme, and executing the PHP file via an HTTP GET request to /themes/<php_file_name>
How severe is CVE-2020-28693?: CVE-2020-28693 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-28693 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-28693?: CVE-2020-28693 affects Horizontcms Project Horizontcms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-28693?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-28693 published?: CVE-2020-28693 was published on 2020-11-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:horizontcms_project:horizontcms:1.0.0:beta:*:*:*:*:*:*

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