CVE-2026-115591 in Contact Form Plugin
Summary
by MITRE • 10/28/2026
Insertion of Sensitive Information Into Sent Data vulnerability in Supsystic Contact Form by Supsystic contact-form-by-supsystic allows Retrieve Embedded Sensitive Data.This issue affects Contact Form by Supsystic: from n/a through 1.10.5.
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Analysis
by VulDB Data Team • 10/28/2026
The vulnerability identified as an insertion of sensitive information into sent data within the Supsystic Contact Form plugin represents a significant security flaw that compromises the confidentiality of user-submitted content. This issue specifically affects versions of the Contact Form by Supsystic plugin ranging from n/a through version 1.10.5. The core technical deficiency lies in how the application handles and transmits data collected via its contact forms, particularly when processing submissions that may inadvertently include or expose sensitive fields such as passwords, personal identification numbers, or other confidential user details. Instead of properly sanitizing or masking this information before transmission to administrators or storage systems, the plugin allows these values to be embedded directly into outgoing emails or database entries without adequate protection mechanisms.
From a technical perspective, this flaw stems from insufficient input validation and output encoding practices during the form submission process. When a user fills out a contact form that includes fields designated for sensitive data, such as password reset tokens or authentication credentials, the application fails to strip these elements before sending them via email notifications or storing them in plain text within its internal database structures. This behavior violates fundamental principles of secure software development regarding the handling of Personally Identifiable Information and other regulated data types. The lack of proper filtering allows attackers who have access to server logs, email archives, or direct database queries to retrieve this embedded sensitive data with relative ease, bypassing any intended privacy controls.
The operational impact of this vulnerability is severe for organizations relying on this plugin for customer communication. If an attacker gains unauthorized access to the administrative emails associated with the contact form submissions, they can harvest credentials that users may have mistakenly entered into these fields. This scenario often arises when developers incorrectly use standard email forms for password recovery or authentication purposes rather than dedicated secure endpoints. The exposure of such data facilitates further attacks including account takeover, credential stuffing, and social engineering campaigns against affected end-users. Furthermore, the leakage of personal information can lead to non-compliance with regulatory frameworks such as GDPR, HIPAA, or CCPA, resulting in potential legal liabilities and reputational damage for the organization hosting the vulnerable application.
This vulnerability aligns closely with CWE-209, which describes the generation of error messages containing sensitive information that could be exploited by attackers, although in this specific case, it manifests more broadly as CWE-359: Exposure of Private Information to an Unauthorized Actor. In terms of attack vectors and tactics, this flaw relates to ATT&CK technique T1504, specifically Web Session Hacking or data exfiltration via compromised application logic where sensitive payloads are intercepted during transit. The vulnerability essentially creates a side-channel through which confidential data escapes the intended boundary of secure processing.
To mitigate this risk, immediate action is required for all systems running Supsystic Contact Form versions up to 1.10.5. Administrators should upgrade to the latest patched version released by Supsystic as soon as it becomes available, ensuring that developers have implemented proper data sanitization and encryption protocols for sensitive fields. In the interim, organizations must audit their form configurations to ensure no password or authentication-related inputs are ever included in standard contact forms. Implementing additional web application firewall rules can help detect anomalous patterns of data transmission involving high-sensitivity keywords. Regular security assessments and code reviews focusing on input/output handling will further reduce the likelihood of similar vulnerabilities emerging in future updates, reinforcing a defense-in-depth strategy against information leakage attacks.