What is the CVSS score of CVE-2020-37023?

CVE-2020-37023 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of PHP are affected by CVE-2020-37023?

Koken CMS 0.22.24 contains a critical file upload flaw that allows authenticated users to upload malicious code by bypassing file restrictions, potentially leading to complete server compromise and…

Is there a public PoC exploit available for CVE-2020-37023?

Yes, a public proof-of-concept exploit is available for CVE-2020-37023. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2020-37023?

Within 24 hours: Audit all user accounts with upload permissions and disable unnecessary access; review recent file uploads for suspicious activity. Within 7 days: Isolate or take offline any Koken CMS 0.22.24 instances if feasible, or implement network segmentation to restrict administrative access. Within 30 days: Migrate to an alternative CMS solution or contact Koken developers for security updates; if remaining on this version, deploy strict file upload validation at the WAF/reverse proxy layer.

PHP CVE-2020-37023

HIGH

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

2026-01-30 disclosure@vulncheck.com

PHP

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:00 vuln.today

PoC Detected

Feb 04, 2026 - 16:34 vuln.today

Public exploit code

CVE Published

Jan 30, 2026 - 23:16 nvd

HIGH 8.8

DescriptionCVE.org

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.

AnalysisAI

Koken CMS 0.22.24 contains a file upload vulnerability that allows authenticated attackers to bypass file extension restrictions by renaming malicious PHP files. [CVSS 8.8 HIGH]

Technical ContextAI

Classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). 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.

Affected ProductsAI

Koken CMS 0.22.24 contains a file upload vulnerability that allows authenticated attackers to bypass file extension restrictions by renaming malicious

RemediationAI

Monitor vendor advisories for a patch. Validate file types by content. Store uploads outside web root. Restrict network access to the affected service where possible.