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List permission bypass in multiple hotpaths

Moderate
knadh published GHSA-85j8-5c6w-gcpv Mar 31, 2026

Package

gomod knadh/listmonk (Go)

Affected versions

>= v4.1.0

Patched versions

v6.1.0

Description

Summary

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.

A single CVE is assigned to reports of the same issue across multiple hotpaths from multiple authors listed below:

  • Send test e-mails to subscribers in lists that a user does not have access to - @PratikKaran23 @VarshankNaik
  • Import subscribers from a CSV to a list a user doesn't have access to - @PratikKaran23
  • Bulk management options on the UI (modify, reassign, blocklist) on subscribers in a list a user doesn't have access to - @Amemoyoi
  • Export subscriber info JSON from admin of a subscriber in a list a user doesn't have access to - @Amemoyoi

These all stem from the same class of permission check issue which is now fixed in a single commit: 347f597. Upgrade to v6.1.0 to fix.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVE ID

CVE-2026-34584

Weaknesses

Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Learn more on MITRE.

Credits