What is CVE-2023-53933?

CVE-2023-53933 is a high-severity vulnerability in S9y Serendipity, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2025-12-17.

How severe is CVE-2023-53933?

High severity. CVSS v3 base score is 8.8 out of 10.

Arbitrary file upload in S9y Serendipity

CVE-2023-53933

Serendipity 2.4.0 contains a remote code execution vulnerability that allows authenticated attackers to upload malicious PHP files with .phar extension. Attackers can upload files with system command payloads to the media upload endpoint a…

Vulnerability class: Unrestricted File Upload

EPSS: 0.006 (70.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

S9y Serendipity — versions 2.4.0

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

ExploitDB-51372 (exploit)
Official Product Homepage (product)
VulnCheck Advisory: Serendipity 2.4.0 Authenticated Remote Code Execution via File Upload (third-party-advisory)

Frequently asked questions

What is CVE-2023-53933?: CVE-2023-53933 is a high-severity vulnerability in S9y Serendipity, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2025-12-17.
How severe is CVE-2023-53933?: High severity. CVSS v3 base score is 8.8 out of 10.