CVE-2026-66067

MEDIUM
MEDIUM Priority: 0.03 BB Relevance: 62/100
Published: 2026-09-23 Modified: 2026-10-30 First seen: 2026-10-30 Status: active

Attack Surface

Network Low Complexity No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: X
AT: Present
VC: None
VI: None
VA: High

Description

RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, The stream open handler calls only check_vhost_access; it omits the node/vhost/user connection-limit checks that rabbit_reader performs for AMQP. A developer %% FIXME comment at the cited line explicitly acknowledges the gap. No compensating enforcement exists in connection tracking or elsewhere in rabbitmq_stream. An authenticated tenant can fully bypass operator-configured per-user and per-vhost connection caps by connecting via port 5552 instead of 5672. Preconditions include rabbitmq_stream plugin enabled Authenticated stream-protocol credentials Operator relies on per-user/per-vhost connection limits for tenant isolation. This issue is fixed in versions 4.2.7 and 4.3.1.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
broadcom rabbitmq_server 4.2.0 – 4.2.7

Bug Bounty Relevance

62 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

6.0 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.44%
Raw Score 0.004370
Percentile 38.0%
Date 2026-10-31

EPSS Trend

2026-10-31
0.00437
2026-10-30
0.00351

Intelligence Sources

nvd ref →