CVE-2025-3929Network attack vector

Stored XSS via unsanitized image-tag JavaScript

Published Apr 29, 2025 · Updated Apr 29, 2025

Stored XSS in MDaemon Email Server 25.0.1 and earlier allows remote attackers to access webmail user data through a crafted HTML email. MDaemon Webmail renders JavaScript embedded in an img tag from a stored email without neutralizing it before the message reaches the browser. The recipient must open the message in Webmail, after which the script runs in that user's browser context and can read accessible account data.

CVSS severity6.1
Medium
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in MDaemon Email Server 25.0.1 and earlier allows remote attackers to access webmail user data through a crafted HTML email. MDaemon Webmail renders JavaScript embedded in an img tag from a stored email without neutralizing it before the message reaches the browser. The recipient must open the message in Webmail, after which the script runs in that user's browser context and can read accessible account data.

The record

CVE
CVE-2025-3929
Published
Apr 29, 2025
Updated
Apr 29, 2025
Vendor
MDaemon Technologies
Product
MDaemon Email Server
Classifications
CWE-79, T1204, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=0 <=25.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MDaemon Technologies · MDaemon Email Serverversion=0 <=25.0.1

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3ESETCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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')
T1204User Execution
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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

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Your stack

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