# CVE-2025-34400: MailEnable < 10.54 Reflected XSS in AddressesTo Parameter of AddressBook.aspx

> Remote attackers can execute arbitrary JavaScript in victims' browsers via a reflected XSS vulnerability in the MailEnable address book, potentially stealing cookies or hijacking sessions.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Dec 2025
- **Updated:** 14 May 2026
- **Also known as:** GHSA-cqhq-3vgx-2rc7

## What is CVE-2025-34400?

CVE-2025-34400 is a medium-severity cross-site scripting vulnerability in Mailenable Mailenable, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

MailEnable versions prior to 10.54 contain a reflected cross-site scripting (XSS) vulnerability in the AddressesTo parameter of /Mondo/lang/sys/Forms/AddressBook.aspx. The AddressesTo value is not properly sanitized when processed via a GET request and is reflected within a <script> block in the response. By supplying a crafted payload that terminates the existing JavaScript 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, inject arbitrary HTML or CSS, and perform actions as the authenticated user.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-34400?

It affects 1 product.


Products: Mailenable Mailenable.

## How do I fix CVE-2025-34400?

No fix has been published for CVE-2025-34400 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-34400 being exploited?

There is no known exploitation of CVE-2025-34400 in the wild and no public exploit code.

## Other vulnerabilities in Mailenable Mailenable

- [CVE-2015-9280](https://insights.sbomify.com/CVE-2015-9280/): XML external entity in n/a (critical 10.0)
- [CVE-2025-44148](https://insights.sbomify.com/CVE-2025-44148/): Cross-site scripting in n/a (critical 9.8)
- [CVE-2019-12924](https://insights.sbomify.com/CVE-2019-12924/): XML external entity in n/a (critical 9.8)
- [CVE-2015-9278](https://insights.sbomify.com/CVE-2015-9278/): MailEnable before 8.60 allows Privilege Escalation because admin accounts could be created as a consequence of %0A mishandling in AUTH.TAB a (critical 9.8)
- [CVE-2015-9277](https://insights.sbomify.com/CVE-2015-9277/): Path traversal in n/a (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-34400 and fix it if it is affected.

What it is: CVE-2025-34400 is a medium-severity cross-site scripting vulnerability in Mailenable Mailenable, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-34400 in the wild and no public exploit code.

Affected product: Mailenable Mailenable. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-34400/ (Markdown: https://insights.sbomify.com/CVE-2025-34400/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-34400
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-34400
- OSV: https://osv.dev/vulnerability/CVE-2025-34400

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-34400/
Summaries are generated and may contain mistakes; the official description above is the record.