CVE-2026-75872

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.

CVSS 4.0

6.9CVSS: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

0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-25)

CWE

CWE-80

Published

2026-08-18

Modified

2026-10-22

Record from

the NVD, synced 2026-10-23

References

• https://github.com/maalfer/mailerup/commit/da4aedc9621911df4ce0cc8f0b321dd6d10f40a5
• https://github.com/maalfer/mailerup/releases/tag/v1.1.3
• https://secur0.com/en/cna/cve-list/cve-2026-75872-html-injection-in-mailerup-double-optin-verification-email

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