CVE-2026-25767
📋 TL;DR
In LavinMQ versions before 2.6.8, authenticated users with the 'Policymaker' management tag can bypass access controls to create shovels, allowing them to read messages from or publish messages to virtual hosts they are not authorized to access. This affects any LavinMQ deployment with authenticated users who have the Policymaker tag.
💻 Affected Systems
- LavinMQ
📦 What is this software?
Lavinmq by 84codes
⚠️ Risk & Real-World Impact
Worst Case
An authenticated malicious insider with Policymaker privileges could exfiltrate sensitive message data from unauthorized vhosts or inject malicious messages into critical queues, potentially leading to data breaches or system compromise.
Likely Case
Accidental or intentional misuse by authorized users to access message queues they shouldn't have access to, violating data segregation policies and potentially exposing sensitive information.
If Mitigated
Limited impact if strict access controls are already in place and Policymaker users are trusted, but still violates the principle of least privilege.
🎯 Exploit Status
Requires authenticated access with Policymaker privileges. Exploitation involves creating shovels with misconfigured access controls to bypass vhost restrictions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.6.8
Vendor Advisory: https://github.com/cloudamqp/lavinmq/security/advisories/GHSA-wh37-6vrr-r9wg
Restart Required: No
Instructions:
1. Backup your LavinMQ configuration and data. 2. Stop LavinMQ service. 3. Upgrade to version 2.6.8 or later using your package manager or from source. 4. Start LavinMQ service. 5. Verify the upgrade was successful.
🔧 Temporary Workarounds
Remove or Restrict Policymaker Users
allTemporarily remove the Policymaker tag from users who don't absolutely need it, or restrict their access to only necessary vhosts.
lavinmqctl set_user_tags <username> <new_tags>
lavinmqctl clear_permissions -p <vhost> <username>
lavinmqctl set_permissions -p <vhost> <username> <configure> <write> <read>
Disable Shovel Creation
allImplement policy to prevent creation of new shovels by Policymaker users until patched.
Monitor and audit shovel creation via logs
Implement external controls to block shovel API calls
🧯 If You Can't Patch
- Implement strict network segmentation to limit access to LavinMQ management interfaces
- Enhance monitoring and alerting for unauthorized shovel creation attempts and unusual message flow patterns
🔍 How to Verify
Check if Vulnerable:
Check LavinMQ version: if version is less than 2.6.8 and you have users with Policymaker tag, you are vulnerable.Check Version:
lavinmqctl status | grep 'LavinMQ' or check server startup logsVerify Fix Applied:
After upgrading, verify version is 2.6.8 or higher and test that Policymaker users cannot create shovels that bypass vhost access controls.📡 Detection & Monitoring
Log Indicators:
- Unauthorized shovel creation attempts
- Shovel configurations referencing vhosts the user shouldn't access
- Unexpected message flow between vhosts
Network Indicators:
- Unusual API calls to shovel management endpoints from Policymaker users
- Unexpected message traffic patterns
SIEM Query:
source="lavinmq.log" AND ("shovel" AND "created" OR "configured") AND user.tag="Policymaker"🔗 References
- https://github.com/cloudamqp/lavinmq/commit/3a83e5894495b60c7c32a79c3dbc9bd9fa237d9a
- https://github.com/cloudamqp/lavinmq/commit/be03da31f3db1a2552f7094ff58e953ef50cdc82
- https://github.com/cloudamqp/lavinmq/pull/1670
- https://github.com/cloudamqp/lavinmq/pull/1687
- https://github.com/cloudamqp/lavinmq/security/advisories/GHSA-wh37-6vrr-r9wg
