CVE-2026-67226 rabbitmq CVE debrief

Who should care

RabbitMQ administrators and users with administrative access to RabbitMQ management interfaces should assess exposure and verify their version. They should also review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. Additionally, they should plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. Those with exposure should also review compensating

Why it matters

CVE-2026-67226 is a medium-severity vulnerability in RabbitMQ that can cause a node crash. Administrators should verify their version, update if necessary, and restrict access to mitigate the issue.

• Verify RabbitMQ version to determine exposure
• Update to a fixed version to prevent node crashes
• Restrict administrative access to mitigate the issue
• Monitor logs for suspicious activity

Technical summary

The vulnerability exists in RabbitMQ versions from 4.0.0 to 4.0.21, 4.1.0 to 4.1.13, and 4.2.0 to 4.2.6. An administrator can create a user with a large number of unique tags, causing an atom exhaustion issue that can crash the node. The issue is caused by the settags/2 function mapping rabbitdatacoercion:toatom/1 over the user's tags list, which can lead to an atom exhaustion issue. The 20 MB management body limit fits ~3-4M short tag strings. This issue is fixed in RabbitMQ versions 4.0.22, 4.1.14, and 4.2.7. The fix involves updating to a version of RabbitMQ that limits the number of tags a user can have or restricts

Defensive priority

Administrators of RabbitMQ servers should verify their version and update to a fixed version if necessary.

Recommended defensive actions

• Verify RabbitMQ version and update to 4.0.22, 4.1.14, or 4.2.7 if necessary
• Restrict administrative access to RabbitMQ management interfaces
• Monitor RabbitMQ logs for suspicious activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability and fixed versions. The issue is caused by the settags/2 function mapping rabbitdatacoercion:toatom/1 over the user's tags list, which can lead to an atom exhaustion issue. The 20 MB management body limit fits ~3-4M short tag strings. Evidence of the vulnerability's existence and impact is limited to the information provided in the CVE record and NVD entry. Further verification and review of the RabbitMQ codebase and documentation are necessary to fully understand the

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.