CVE-2026-67411RabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass
Updated under an hour ago ()
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It affects rabbitmq-server and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3, native MQTT and MQTT over WebSocket behind a trusted PROXY Protocol frontend could lose the proxy-derived client address before the MQTT authentication path checked loopback_users, causing the frontend-to-broker address to be treated as loopback. An attacker who can reach the trusted frontend and has valid credentials for a loopback-restricted account can therefore bypass the source-address restriction; the issue does not bypass password authentication. This issue is fixed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3.
- CVSS
- 6.0 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-863
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Sep 25, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
rabbitmq rabbitmq-server rabbitmq:server (from the name) | from 4.3.0, < 4.3.3; from 4.2.0, < 4.2.9; from 4.1.0, < 4.1.14; from 4.0.0, < 4.0.23; from 3.13.0, < 3.13.18 | CNA record |
broadcom rabbitmq_server broadcom:rabbitmq_server | from 3.13.0 before 3.13.18; from 4.0.0 before 4.0.23; from 4.1.0 before 4.1.14; from 4.2.0 before 4.2.9; from 4.3.0 before 4.3.3 | NVD |
References
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6x-refsource-confirm, exploit, vendor-advisory
- https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349x-refsource-misc, patch
- https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646x-refsource-misc, patch
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9x-refsource-misc, release-notes
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3x-refsource-misc, release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.