CVE-2026-128334

Description

listmonk 6.2.0 before 7.0.0-beta.2 contains a missing authentication vulnerability that allows unauthenticated attackers to submit Azure Event Grid bounce webhooks when no shared secret is configured. Attackers can POST forged EmailDeliveryReportReceived events with Bounced status to /webhooks/service/azure to blocklist, unsubscribe, or delete arbitrary subscribers.

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

• 6.3CVSS 4.0, Mediumfrom the CNA (VulnCheck)CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
• 4.8CVSS 3.1, Mediumfrom the CNA (VulnCheck)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Timeline

1. 13 Nov 2026 Published

Weakness

• CWE-636

References

• github.compatch
• listmonk v7.0.0-beta.2 Release Notesrelease-notes
• github.comtechnical-description
• github.comissue-tracking
• VulnCheck Advisory: listmonk 6.2.0 before 7.0.0-beta.2 Missing Authentication via Azure Bounce Webhookthird-party-advisory