HTML Injection in MailerUp double opt-in verification email

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-75872
StatePUBLISHED
AssignerSecur0
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-18 15:17:15 UTC
Updated2026-08-18 16:18:21 UTC
DescriptionHTML Injection in the public subscription form in maalfer MailerUp before 1.1.3 allows unauthenticated remote attackers to have the application send a message carrying arbitrary HTML, to an attacker-chosen address and from the form owner's configured sending identity, via the first_name field of the subscription request, which is interpolated unescaped into the double opt-in verification email.

Risk And Classification

Primary CVSS: v4.0 6.9 MEDIUM from 4daa8cea-433a-44bd-9456-53b127fc289a

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-80 | CWE-80 CWE-80 Improper neutralization of Script-Related HTML tags in a web page (basic XSS)

VersionSourceTypeScoreSeverityVector
4.04daa8cea-433a-44bd-9456-53b127fc289aSecondary6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Maalfer MailerUp affected 1.1.3 semver Not specified

References

ReferenceSourceLinkTags
github.com/maalfer/mailerup/releases/tag/v1.1.3 4daa8cea-433a-44bd-9456-53b127fc289a github.com
github.com/maalfer/mailerup/commit/da4aedc9621911df4ce0cc8f0b321dd6d10f40a5 4daa8cea-433a-44bd-9456-53b127fc289a github.com
secur0.com/en/cna/cve-list/cve-2026-75872-html-injection-in-mailerup-dou... 4daa8cea-433a-44bd-9456-53b127fc289a secur0.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Nacho García Egea (en)

CNA: Xoán M. Otero Jorge (en)

CNA: Secur0 CNA (en)

CNA: Mario Álvarez Fernández (en)

Additional Advisory Data

Solutions

CNA: Upgrade to version 1.1.3 or higher.

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