CVE-2023-53956

Name: CVE-2023-53956
Creator: NVD / NIST
Published: 2025-12-19T21:15:51.97+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.7/10EPSS 0.66%

Last modified Jun 17, 2026

CVE-2023-53956 is a high-severity vulnerability rated 8.7/10 on the CVSS scale. Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager. Attackers with admin credentials can upload malicious PHP scripts to the web root directory, enabling remote code execution on the server.. EPSS estimates a 0.66% chance of exploitation in the next 30 days.

Description

Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager. Attackers with admin credentials can upload malicious PHP scripts to the web root directory, enabling remote code execution on the server.

Metrics

CVSS 3.1

8.8/10

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

CVSS 4.0

8.7/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.66%

47.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

References

Timeline

Published: Dec 19, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2023-53956?

How severe is CVE-2023-53956?

CVE-2023-53956 has a CVSS score of 8.7/10 (HIGH severity). The EPSS model estimates a 0.66% probability of exploitation in the next 30 days.

How do I fix CVE-2023-53956?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-53956?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST