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.
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History

Fri, 25 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title RabbitMQ: AMQP 1.0 management exchange.declare skips alternate-exchange permission check
Weaknesses CWE-862
References
Metrics cvssV4_0

{'score': 4.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-25T16:12:14.689Z

Reserved: 2026-07-28T19:50:39.438Z

Link: CVE-2026-67241

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T17:17:12.180

Modified: 2026-09-25T17:17:12.180

Link: CVE-2026-67241

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses