TI-2026-26831 Aliases CVE-2026-34584

listmonk: Broken Access Control in CSV Import (Unauthorized List Assignment)

LOW 24CWE-639Published 2026-04-02 · Updated 2026-04-02

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: Low · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00178 7th percentileScored 2026-11-07

Fix Fixed listmonk (knadh): 6.1.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
knadh	listmonk	4.1.0 to before 6.1.0	6.1.0	Patch available	CNA

listmonk Vendorknadh Affected 4.1.0 to before 6.1.0 Fixed in 6.1.0 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:nadh:listmonk::::::::	4.1.0 to before 6.1.0	Vulnerable	knadh

cpe:2.3:a:nadh:listmonk:*:*:*:*:*:*:*:* Versions 4.1.0 to before 6.1.0 Vulnerable ·knadh

Remediation

Fix · CNA listmonk (knadh) Fixed in 6.1.0

Timeline

2026-10-02 Threatist record created from CVE-2026-34584

References

Patch 2

Other 1

https://github.com/knadh/listmonk/releases/tag/v6.1.0

TI-2025-31216 listmonk's Sprig template Injection vulnerability leads to reading of Environment Variable for low privilege user CVSS 3.1CRITICAL 9.1
TI-2025-36190 listmonk Vulnerable to CSRF to XSS Chain That Can Lead to Admin Account Takeover CVSS 4.0HIGH 8.6
TI-2026-27072 listmonk: Active sessions remain valid after password reset and password change CVSS 3.1HIGH 7.1
TI-2026-17337 listmonk Vulnerable to Stored XSS Leading to Admin Account Takeover CVSS 4.0MEDIUM 5.4
TI-2025-28914 Listmonk v4.1.0 (fixed in v5.0.0) is vulnerable to SQL Injection in the QuerySubscribers… CVSS 3.1MEDIUM 6.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences