Vulnerability · Published Apr 2, 2026 · Assigned by GitHub_M

CVE-2026-34584listmonk: Broken Access Control in CSV Import (Unauthorized List Assignment)

Medium 5.4

In plain English

A medium-severity authorization bypass via user-controlled key in listmonk from knadh. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.2%top 92.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
knadh	listmonk	>= 4.1.0, < 6.1.0

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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