Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-67411

CVE-2026-67411MEDIUM

RabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   H   P   L   N   H   N   N    6.0   .0032   23.2     —

AFFECTED
  Product          Versions             Fixed
  rabbitmq-server  >= 4.3.0, < 4.3.3 –  —

TIMELINE
  Jul 29  Reserved by GitHub_M
  Sep 25  Published (CNA: GitHub_M)
  Oct 8   EXPLOIT PUBLISHED — CVE-2026-67411 (rabbitmq-server). Public exploit reference added.

CWE-863 · CNA: GitHub_M · CVSS v4.0 · 5 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 29, 2026	Reserved	Reserved by GitHub_M
September 25, 2026	Published	Published (CNA: GitHub_M)
October 8, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-67411 (rabbitmq-server). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
rabbitmq	rabbitmq-server	—	>= 4.3.0, < 4.3.3	—

Weaknesses

CWE-863

References (5)

https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349 [Patch]
https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646 [Patch]
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9 [Release Notes]
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3 [Release Notes]
https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6 [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-67411 at cve.org

Vendors: rabbitmq

Weaknesses: CWE-863

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-67411 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.