What is CVE-2026-34584?

CVE-2026-34584 is a medium-severity vulnerability in Knadh Listmonk, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.4/10. Published 2026-04-02.

How severe is CVE-2026-34584?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Auth bypass in Knadh Listmonk

CVE-2026-34584

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 acces…

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.000 (10.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Knadh Listmonk — versions >= 4.1.0, < 6.1.0

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

https://github.com/knadh/listmonk/security/advisories/GHSA-85j8-5c6w-gcpv (x_refsource_CONFIRM)
https://github.com/knadh/listmonk/commit/347f5976759232c36e571cf58b4bfe33c2794f35 (x_refsource_MISC)
https://github.com/knadh/listmonk/releases/tag/v6.1.0 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-34584?: CVE-2026-34584 is a medium-severity vulnerability in Knadh Listmonk, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.4/10. Published 2026-04-02.
How severe is CVE-2026-34584?: Medium severity. CVSS v3 base score is 5.4 out of 10.