CVE-2025-59902 Overview
CVE-2025-59902 is an HTML injection vulnerability affecting NICE Chat. This vulnerability allows an attacker to inject and render arbitrary HTML content in email transcripts by modifying the firstName and lastName parameters during a chat session. The injected HTML is included in the body of the email sent by the system, which could enable phishing attacks, impersonation, or credential theft.
Critical Impact
Attackers can exploit this vulnerability to inject malicious HTML content into email transcripts, potentially leading to phishing attacks, credential theft, and impersonation of legitimate users or support staff.
Affected Products
- NICE Chat (specific versions not disclosed)
Discovery Timeline
- 2026-02-03 - CVE-2025-59902 published to NVD
- 2026-02-03 - Last updated in NVD database
Technical Details for CVE-2025-59902
Vulnerability Analysis
This HTML injection vulnerability (CWE-79) exists in the NICE Chat application's email transcript functionality. When users engage in chat sessions, the system captures user-provided information including the firstName and lastName parameters. These values are subsequently embedded into email transcripts without proper sanitization or encoding.
The vulnerability enables attackers to craft malicious input containing HTML markup that gets rendered when the email transcript is viewed. This can be particularly dangerous in enterprise environments where chat transcripts are routinely emailed to customers or internal staff for record-keeping purposes.
Root Cause
The root cause of this vulnerability is insufficient input validation and output encoding in the NICE Chat application. The firstName and lastName parameters accept arbitrary HTML content without sanitization. When the system generates email transcripts, this unsanitized input is directly embedded into the HTML body of the email, allowing the injected markup to be interpreted and rendered by email clients.
Attack Vector
The attack is network-based and requires user interaction. An attacker initiates a chat session with the NICE Chat application and provides malicious HTML content in the firstName or lastName fields. When the chat transcript is emailed—either automatically or upon request—the injected HTML is rendered in the recipient's email client.
Attackers could leverage this to:
- Create convincing phishing forms within legitimate email transcripts
- Inject fake login prompts to harvest credentials
- Impersonate support staff or company representatives
- Redirect users to malicious external sites via injected links
The vulnerability is exploited by supplying HTML markup in the name fields during chat session initiation. For example, an attacker could inject form elements, script references, or styled content that appears legitimate within the context of an official email transcript. Detailed technical information is available in the INCIBE Security Notice.
Detection Methods for CVE-2025-59902
Indicators of Compromise
- Email transcripts containing unexpected HTML elements, forms, or embedded iframes
- Chat logs showing suspicious markup in user name fields such as <form>, <script>, <img>, or <a> tags
- Reports from users receiving phishing attempts via official chat transcript emails
- Unusual patterns in chat session data with HTML-encoded characters in identity fields
Detection Strategies
- Implement email content scanning to detect and flag transcripts containing unexpected HTML elements
- Monitor chat session logs for HTML tags in the firstName and lastName parameters
- Deploy email security solutions that can identify and quarantine messages with suspicious embedded content
- Create alerts for email transcripts originating from the chat system that contain form elements or external links
Monitoring Recommendations
- Enable logging for all chat session parameter inputs and review for anomalous content
- Configure email gateway rules to inspect and report on chat transcript emails containing HTML beyond expected formatting
- Establish baseline patterns for legitimate chat transcripts to identify deviations
- Monitor user complaints and security reports related to suspicious content in chat-generated emails
How to Mitigate CVE-2025-59902
Immediate Actions Required
- Implement strict input validation on all user-supplied parameters in the NICE Chat application
- Apply HTML entity encoding to all user-provided content before including it in email transcripts
- Review and audit recent email transcripts for signs of exploitation
- Educate users about potential phishing attempts via manipulated chat transcripts
Patch Information
Consult the INCIBE Security Notice for the latest vendor guidance and patch availability. Organizations should contact NICE directly for official security updates and patching instructions.
Workarounds
- Implement server-side input sanitization to strip HTML tags from name fields before storage
- Configure email systems to render chat transcripts in plain text mode only
- Apply Content Security Policy headers if transcripts are also viewable via web interface
- Consider temporarily disabling the email transcript feature until a patch is applied
# Example input sanitization approach (conceptual)
# Strip HTML tags from user input before processing
# Encode special characters: < > " ' &
# Validate input against allowlist of permitted characters
# Configure email templates to escape all dynamic content
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
