CVE-2026-0829 in Frontend File Manager Plugin
Summary
by MITRE • 02/17/2026
The Frontend File Manager Plugin WordPress plugin through 23.5 allows unauthenticated users to send emails through the site without any security checks. This lets attackers use the WordPress site as an open relay for spam or phishing emails to anyone. Attackers can also guess file IDs to access and share uploaded files without permission, exposing sensitive information.
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Analysis
by VulDB Data Team • 02/18/2026
The vulnerability identified as CVE-2026-0829 affects the Frontend File Manager WordPress plugin version 23.5 and earlier, presenting a critical security flaw that compromises the integrity and confidentiality of WordPress installations. This vulnerability stems from inadequate authentication mechanisms within the plugin's email functionality, allowing any unauthenticated user to leverage the WordPress site as an open relay for malicious email communications. The flaw represents a significant deviation from standard security practices where email services should enforce proper authentication and authorization checks before processing email requests.
The technical implementation of this vulnerability manifests through the plugin's failure to validate user credentials when processing email sending requests. This design flaw creates an unrestricted access point where attackers can submit email payloads without any form of authentication verification. The vulnerability maps directly to CWE-306, which addresses missing authentication checks, and aligns with ATT&CK technique T1192, which involves the use of open relay for spam distribution. The plugin's email functionality lacks proper input validation and access control mechanisms, enabling attackers to exploit this weakness for mass email campaigns.
The operational impact of this vulnerability extends beyond simple spam distribution, as it creates a vector for sophisticated phishing attacks that can target unsuspecting users. Attackers can craft convincing email content that appears to originate from the compromised WordPress site, increasing the likelihood of successful social engineering campaigns. Additionally, the vulnerability exposes the plugin's file management system to unauthorized access through predictable file ID guessing mechanisms, creating a secondary attack surface for data exfiltration. This dual vulnerability creates a comprehensive attack vector that can be exploited for both email-based and file-based malicious activities.
The exposure of sensitive information through unauthorized file access represents a significant confidentiality breach, as attackers can potentially access documents, images, or other uploaded content that should remain restricted to authorized users. This file access vulnerability demonstrates a lack of proper access control implementation and violates fundamental security principles of least privilege and access validation. Organizations using affected plugin versions face potential reputational damage, regulatory compliance issues, and increased risk of further compromise through the use of the WordPress site as a launching point for additional attacks.
Mitigation strategies should include immediate plugin updates to versions that address the authentication and access control vulnerabilities. System administrators should implement additional security measures such as email rate limiting, content filtering, and monitoring for unusual email activity patterns. Network-level protections including email filtering solutions and firewall rules can help limit the impact of open relay exploitation. The vulnerability highlights the importance of proper security testing and code review processes, particularly for plugins that handle user input and external communications. Organizations should also consider implementing automated vulnerability scanning and monitoring solutions to detect similar issues in other WordPress components and third-party plugins.