How severe is CVE-2020-37023?

CVE-2020-37023 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-2020-37023 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2020-37023?

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.

Does CVE-2020-37023 have an EU (EUVD) identifier?

Yes. CVE-2020-37023 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-30953.

When was CVE-2020-37023 published?

CVE-2020-37023 was published on 2026-01-30 and last updated on 2026-06-17.

CVE-2020-37023

CVE-2020-37023 is a high-severity vulnerability 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 v4: 8.7
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2020-30953
Weakness: CWE-434
Published: 2026-01-30
Last modified: 2026-06-17

Description

Koken CMS 0.22.24 contains a file upload vulnerability that allows authenticated attackers to bypass file extension restrictions by renaming malicious PHP files. Attackers can upload PHP files with system command execution capabilities by manipulating the file upload request through a web proxy and changing the file extension.

Frequently asked questions

What is CVE-2020-37023?: Koken CMS 0.22.24 contains a file upload vulnerability that allows authenticated attackers to bypass file extension restrictions by renaming malicious PHP files. Attackers can upload PHP files with system command execution capabilities by manipulating the file upload request through a web proxy and changing the file extension.
How severe is CVE-2020-37023?: CVE-2020-37023 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-2020-37023 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2020-37023?: 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.
Does CVE-2020-37023 have an EU (EUVD) identifier?: Yes. CVE-2020-37023 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-30953.
When was CVE-2020-37023 published?: CVE-2020-37023 was published on 2026-01-30 and last updated on 2026-06-17.

References

Other CWE-434 (Unrestricted Upload of File with Dangerous Type) vulnerabilities

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CVE-2026-40772 — Critical (CVSS 10.0): Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions.
CVE-2026-40412 — Critical (CVSS 10.0): Unrestricted upload of file with dangerous type in Azure Orbital Spatio allows an unauthorized attacker to execute code…

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