CVE-2026-34584 listmonk: Broken Access Control in CSV Import (Unauthorized List Assignment)
Unauthorized users can access and modify mailing lists they lack permissions for in multi-user environments.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-34584?
CVE-2026-34584 is a medium-severity missing authorization vulnerability in knadh listmonk, published on 2 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
listmonk is a standalone, self-hosted, newsletter and mailing list manager. From version 4.1.0 to before version 6.1.0, bugs in list permission checks allows users in a multi-user environment to access to lists (which they don't have access to) under different scenarios. This only affects multi-user environments with untrusted users. This issue has been patched in version 6.1.0.
Weakness: CWE-639
Which versions are affected by CVE-2026-34584?
It affects 1 product.
Products include Nadh Listmonk.
How do I fix CVE-2026-34584?
No fix has been published for CVE-2026-34584 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-34584 being exploited?
There is no known exploitation of CVE-2026-34584 in the wild and no public exploit code.
Other vulnerabilities in knadh listmonk
- CVE-2025-49136 listmonk's Sprig template Injection vulnerability leads to reading of Environment Variable for low privilege user
- CVE-2025-58430 listmonk Vulnerable to CSRF to XSS Chain That Can Lead to Admin Account Takeover
- CVE-2026-34828 listmonk: Active sessions remain valid after password reset and password change
- CVE-2025-46011 SQL injection in n/a
- CVE-2026-21483 listmonk Vulnerable to Stored XSS Leading to Admin Account Takeover
Sources
Also known as GHSA-85j8-5c6w-gcpv.