What is the CVSS score of CVE-2026-75872?

CVE-2026-75872 has a CVSS 4.0 base score of 6.9 (Medium). CVSS vector: 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. EPSS exploitation probability: 0.7%.

Is there a patch available for CVE-2026-75872?

Yes, a patch is available for CVE-2026-75872. Update the affected software to the latest version immediately.

Mailerup CVE-2026-75872

EUVD-2026-60820 MEDIUM

Basic XSS (CWE-80)

2026-08-18 Secur0

GHSA-gj4p-rxxg-6jhm

XSS Mailerup Maalfer

6.9

CVSS 4.0 · Vendor: Secur0

View

Vulnerability Assessment

Weakness

CWE

CWE-80

OWASP Top 10:2025

A05:2025 - Injection

ASVS 5.0

V1 - Encoding and Sanitization HTML tag escaping

MITRE ATT&CK

1 technique across 1 tactic: Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

Patch available 0.7% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Aug 18, 2026

HTML injection in MailerUp's public subscription form (all versions before 1.1.3) allows unauthenticated remote attackers to embed arbitrary HTML into the double opt-in verification email the application sends, using the form owner's configured sending identity and an attacker-specified recipient address. The root cause is unescaped interpolation of the subscriber-supplied first_name field directly into the HTML email body, confirmed by the patch commit which adds Django's escape() call. No active exploitation is confirmed in CISA KEV, but the Secur0 CNA advisory fully documents the injection point and patch version 1.1.3 is available.

Affected VersionsENISA

Mailerup 0 <1.1.3

Affected Packages

euvd mailerup fix: 1.1.3

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Know when Mailerup gets its next vulnerability

Watch products and get an email when something new is published
Check this CVE against your own stack and servers
Exploit and PoC references, threat intelligence from 22 sources

Continue with Google Continue with GitHub

No credit card · 7-day full trial

Severity by source

Vendor (Secur0) PRIMARY 6.9 MEDIUM

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

Primary rating from Vendor (Secur0) · only source for this CVE.

CVSS VectorVendor: Secur0

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

None

Vulnerable system: Integrity

Low

Vulnerable system: Availability

None

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

DescriptionCVE.org

HTML 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.

Threat Intelligence Overview

EPSS Score

0.7%

Top 49% exploitable

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC No

EPSS 0.7%

Patch available Yes

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.