CVE-2026-29965
Cross-Site Scripting in HSC MailInspector 5.3.3-7
Publication date: 2026-05-18
Last updated on: 2026-05-19
Assigner: MITRE
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| hsclabs | mailinspector | 5.3.3-7 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
The vulnerability in HSC MailInspector version 5.3.3-7 is a Cross Site Scripting (XSS) issue found in the /police/WarningUrlPage.php endpoint. It occurs because the application does not properly neutralize user-supplied input, allowing attackers to inject malicious scripts using alternate or obfuscated JavaScript syntax.
How can this vulnerability impact me? :
This vulnerability can allow attackers to execute malicious scripts in the context of the affected web application. This can lead to unauthorized actions such as stealing user credentials, hijacking user sessions, or manipulating the content displayed to users. The CVSS score indicates a moderate severity with potential impacts on confidentiality and integrity.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability in MailInspector 5.3.3-7 allows attackers to execute obfuscated JavaScript payloads via a Cross-Site Scripting (XSS) flaw. This can lead to credential theft, session hijacking, fraudulent content injection, and user interface manipulation.
Such impacts can compromise the confidentiality and integrity of user data, potentially violating data protection requirements under standards like GDPR and HIPAA, which mandate safeguarding personal and sensitive information against unauthorized access and manipulation.
Therefore, exploitation of this vulnerability could result in non-compliance with these regulations due to the risk of data breaches and unauthorized data exposure.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by testing the /mailinspector/police/WarningUrlPage.php endpoint for reflected Cross-Site Scripting (XSS) issues. Specifically, you can send crafted HTTP requests with obfuscated or alternate JavaScript payloads in user-supplied input parameters and observe if the payload is reflected and executed in the response.
A common approach is to use tools like curl or specialized web vulnerability scanners to send test payloads. For example, you might use a command like:
- curl -i -s -k "http://[target]/mailinspector/police/WarningUrlPage.php?param=<script>alert(1)</script>"
If the response contains the injected script without proper encoding or neutralization, it indicates the presence of the XSS vulnerability.
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include applying proper input validation and output encoding on the /mailinspector/police/WarningUrlPage.php endpoint to neutralize any user-supplied input that could contain obfuscated JavaScript.
Additionally, consider restricting or sanitizing inputs to disallow script tags or suspicious characters, and update MailInspector to a version where this vulnerability is fixed if available.
As a temporary measure, you may also implement web application firewall (WAF) rules to detect and block suspicious requests targeting this endpoint.