CVE-2025-34398
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedMailEnable versions prior to 10.54 contain a reflected cross-site scripting (XSS) vulnerability in the AddressesBcc parameter of /Mondo/lang/sys/Forms/AddressBook.aspx. The AddressesBcc value is not properly sanitized when processed via a GET request and is reflected within a <script> block in the JavaScript variable var sAddrBcc. By supplying a crafted payload that terminates the existing LoadCurAddresses() function, inserts attacker-controlled script, and comments out remaining code, a remote attacker can execute arbitrary JavaScript in a victim’s browser when the victim attempts to send an email. Successful exploitation can redirect victims to malicious sites, steal non-HttpOnly cookies, and perform actions as the authenticated user.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceMailEnable versions before 10.54 contain a reflected XSS vulnerability in the AddressesBcc parameter on /Mondo/lang/sys/Forms/AddressBook.aspx. The parameter value is not sanitized and is directly reflected into a JavaScript variable (var sAddrBcc) within a script block, allowing attackers to terminate the existing LoadCurAddresses() function and inject arbitrary JavaScript.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.54CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check MailEnable versionLocate the MailEnable installation and determine the installed version. This can typically be found in the Windows registry under HKLM\SOFTWARE\MailEnable\Version, or by accessing the MailEnable Administration program and viewing the About or System Information section.Affected if The installed version is any version prior to 10.54
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Confirm web interface availabilityVerify that the MailEnable web client or administration interface is accessible. The vulnerable page path is /Mondo/lang/sys/Forms/AddressBook.aspx for the web client.Affected if The AddressBook.aspx page is accessible and the MailEnable version is below 10.54
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Test AddressesBcc parameter for reflected inputSubmit a crafted request to the AddressBook.aspx page including the AddressesBcc parameter with a test value such as 'test</script><script>alert(1)</script>'. Inspect the HTTP response to see if this value is reflected unescaped within a JavaScript variable assignment (var sAddrBcc).Affected if The AddressesBcc parameter value is reflected directly into the HTML/JavaScript response without proper encoding or sanitization, allowing script execution
The environment is affected if the installed MailEnable version is below 10.54 and the AddressesBcc parameter on the AddressBook.aspx page reflects user input without encoding, enabling cross-site scripting.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.54
Upgrade to MailEnable 10.54 or later. Additionally, implement proper input validation and output encoding for the AddressesBcc parameter to prevent reflected XSS.
10.54
- 1. Backup the current MailEnable installation and configuration
- 2. Download MailEnable version 10.54 from the official MailEnable website (mailenable.com)
- 3. Install the upgrade following the standard MailEnable upgrade procedure
- 4. Verify the installation completed successfully
- 5. Test the /Mondo/lang/sys/Forms/AddressBook.aspx page to confirm the AddressesBcc parameter is properly sanitized
- 6. Clear any cached files and restart web server services if necessary
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-34398 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-34398 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data