CVE-2026-67241

RabbitMQ: AMQP 1.0 management exchange.declare skips alternate-exchange permission check

MEDIUM
6.5
CVSS Score
Published: September 25, 2026 at 04:12 PM UTC
Updated: October 16, 2026 at 04:31 PM UTC
2 products affected across 2 vendorsRabbitmq ServerRabbitmq Server

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.9 and 4.3.3, AMQP 1.0 management exchange.declare skips alternate-exchange permission check. pUT /exchanges/:name (lines 192-240) checks only configure on the declared exchange and passes XArgs straight to rabbitexchange:declare/7. It omits the checkreadpermitted(X) + checkwritepermitted(AE) that rabbitchannel.erl:2540-2548 enforces for the alternate-exchange argument on the AMQP 0-9-1 path. The same file already implements the analogous DLX check for queues (lines 708-719), confirming this is a missing-check bug rather than intentional A user with only configure on exchange X can route X's unroutable messages into an alternate exchange they have no write permission AMQP 1.0 enabled (default in RabbitMQ 4.x) Attacker has configure on at least one exchange but lacks write on the target. This issue is fixed in versions 4.2.9 and 4.3.3.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.2.0 ≤ v < 4.2.94.3.0 ≤ v < 4.3.3
Affected range stops below 4.2.9, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.3.3, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-862

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