CVE-2025-34398Network attack vector

Arbitrary script execution via unsanitized AddressesBcc reflection

Published Dec 9, 2025 · Updated May 14, 2026

Reflected XSS in MailEnable before 10.54 allows remote attackers to execute arbitrary JavaScript through a crafted AddressesBcc value. AddressBook.aspx places the unsanitized GET value inside the sAddrBcc script variable, allowing input to terminate LoadCurAddresses() and inject script. Exploitation requires a victim with an authenticated webmail session to open the crafted request and attempt to send email, exposing session-accessible data and actions.

CVSS severity5.3
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Reflected XSS in MailEnable before 10.54 allows remote attackers to execute arbitrary JavaScript through a crafted AddressesBcc value. AddressBook.aspx places the unsanitized GET value inside the sAddrBcc script variable, allowing input to terminate LoadCurAddresses() and inject script. Exploitation requires a victim with an authenticated webmail session to open the crafted request and attempt to send email, exposing session-accessible data and actions.

The record

CVE
CVE-2025-34398
Published
Dec 9, 2025
Updated
May 14, 2026
Vendor
MailEnable
Product
MailEnable
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. May 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <10.54

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MailEnable · MailEnableversion=0 <10.54

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo