CVE-2026-21483 Details
Description
listmonk is a standalone, self-hosted, newsletter and mailing list manager. Prior to version 6.0.0, lower-privileged user with campaign management permissions can inject malicious JavaScript into campaigns or templates. When a higher-privileged user (Super Admin) views or previews this content, the XSS executes in their browser context, allowing the attacker to perform privileged actions such as creating backdoor admin accounts. The attack can be weaponized via the public archive feature, where victims simply need to visit a link - no preview click required. Version 6.0.0 fixes the issue.
A stored cross-site scripting vulnerability has been identified in Listmonk versions prior to 6.0.0. Lower-privileged users with campaign management permissions can inject malicious JavaScript into campaigns or templates. When this content is viewed by a higher-privileged user (Super Admin), the injected script executes in their browser, potentially allowing the attacker to perform privileged actions, such as creating backdoor admin accounts. This vulnerability can also be exploited through the public archive feature, where victims need only to visit a link for the XSS to execute, without any interaction required.
Users are advised to update to Listmonk version 6.0.0 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jan 2, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/knadh/listmonk/security/advisories/GHSA-jmr4-p576-v565 | [email protected] | ExploitVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| nadh listmonk | < 6.0.0 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Feb 25, 2026 | Initial Analysis | [email protected] |
| Jan 2, 2026 | New CVE Received | [email protected] |