Cyber Posture

CVE-2025-13543

High

Published: 04 December 2025

Published
04 December 2025
Modified
15 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0007 21.1th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may backdoor web servers with web shells to establish persistent access to systems.

Security Summary

CVE-2025-13543 is an arbitrary file upload vulnerability in the PostGallery plugin for WordPress, affecting all versions up to and including 1.12.5. The issue stems from incorrect file type validation in the 'PostGalleryUploader' class functions, allowing attackers to bypass restrictions and upload malicious files to the server. It carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-434 (Unrestricted Upload of File with Dangerous Type).

Authenticated attackers with subscriber-level permissions or higher can exploit this vulnerability remotely without user interaction. By uploading arbitrary files, such as web shells, they can achieve potential remote code execution on the affected WordPress site, leading to full server compromise including high confidentiality, integrity, and availability impacts.

Advisories reference the vulnerable source code in PostGalleryUploader.php at https://plugins.trac.wordpress.org/browser/postgallery/tags/1.12.5/admin/PostGalleryUploader.php and provide further details via Wordfence threat intelligence at https://www.wordfence.com/threat-intel/vulnerabilities/id/13348eb5-5001-4ec4-bc6a-44795bbed203?source=cve.

Details

CWE(s)
CWE-434

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
Why these techniques?

Arbitrary file upload in public-facing WordPress plugin enables exploitation of public-facing application (T1190) and deployment of web shells for RCE (T1505.003).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References