What is CVE-2024-30503?

CVE-2024-30503 is a high-severity vulnerability in Everpress Mailster, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2024-03-29.

How severe is CVE-2024-30503?

High severity. CVSS v3 base score is 7.1 out of 10.

Is CVE-2024-30503 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Everpress Mailster

CVE-2024-30503

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in EverPress Mailster mailster.This issue affects Mailster: from n/a through <= 4.0.6.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2024-03-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.004 (34.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Everpress Mailster — versions 0
Mailster

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

20142995/nuclei-templates

References

patchstack.com/database/Wordpress/Plugin/mailster/vulnerability/wordpress-mails… (vdb-entry)
af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)

Frequently asked questions

What is CVE-2024-30503?: CVE-2024-30503 is a high-severity vulnerability in Everpress Mailster, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2024-03-29.
How severe is CVE-2024-30503?: High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2024-30503 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.