RabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass
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.
CVE-2026-67411
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-67411
rabbitmq-server
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "rabbitmq",
"product": "rabbitmq-server",
"versions": [
{
"status": "affected",
"version": ">= 4.3.0, < 4.3.3"
},
{
"status": "affected",
"version": ">= 4.2.0, < 4.2.9"
},
{
"status": "affected",
"version": ">= 4.1.0, < 4.1.14"
},
{
"status": "affected",
"version": ">= 4.0.0, < 4.0.23"
},
{
"status": "affected",
"version": ">= 3.13.0, < 3.13.18"
}
]
}
]- Related CVEs
- CVE-2026-67411
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #2192 · Revision 1
- Added to Heist Feed
- Publisher date