Cyber Posture

CVE-2025-26776

Critical

Published: 22 February 2025

Published
22 February 2025
Modified
28 April 2026
KEV Added
Patch
CVSS Score 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0017 38.5th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

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

Security Summary

CVE-2025-26776 is an Unrestricted Upload of File with Dangerous Type vulnerability (CWE-434) in the NotFound Chaty Pro WordPress plugin. It enables attackers to upload a web shell to the web server. The issue affects Chaty Pro versions from n/a through 3.3.3 and was published on 2025-02-22.

The vulnerability carries a CVSS v3.1 base score of 10.0 (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H), indicating it is exploitable over the network with low complexity by unauthenticated attackers requiring no user interaction. Exploitation allows remote attackers to upload arbitrary dangerous files, such as web shells, resulting in high impacts to confidentiality, integrity, and availability, with a changed scope that can lead to server compromise.

The Patchstack advisory provides further details on this arbitrary file upload vulnerability in Chaty Pro 3.3.3 and related mitigation guidance: https://patchstack.com/database/wordpress/plugin/chaty-pro/vulnerability/wordpress-chaty-pro-plugin-3-3-3-arbitrary-file-upload-vulnerability?_s_id=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?

The unrestricted file upload vulnerability in a public-facing WordPress plugin directly enables remote unauthenticated attackers to upload and execute web shells, mapping to T1190 (Exploit Public-Facing Application) for initial exploitation and T1505.003 (Web Shell) for the resulting server compromise.

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

References