Critical severity · published Jul 10, 2026
CVE-2026-57216
RabbitMQ: AMQP 1.0, AMQP 0-9-1, Stream Protocol loopback enforcement can lead to remote guest sessions due to listener-address loopback checks
10.0
CVSS
0.5%
EPSS
No
On KEV
Description
RabbitMQ is a messaging and streaming broker. Prior to 3.13.15, 4.0.20, 4.1.11, and 4.2.6, AMQP 0-9-1, AMQP 1.0, and Stream Protocol authentication can allow a loopback-restricted user such as guest to connect remotely when traffic is accepted through a trusted PROXY-protocol path and the backend listener is loopback-bound because the loopback check uses the listener-side socket address instead of the real client source. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RA
rabbitmq-server · rabbitmq
>= 4.2.0, < 4.2.6; >= 4.1.0, < 4.1.11; >= 4.0.0, < 4.0.21; >= 3.13.0, < 3.13.15 · source: vendor
RS
Rabbitmq Server · Broadcom
3.13.0 before 3.13.15; 4.0.0 before 4.0.20; 4.1.0 before 4.1.11; 4.2.0 before 4.2.6 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-57216
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-57216
Patch
https://github.com/rabbitmq/rabbitmq-server/commit/7273c9eb6920abcde17b892dbe97ccaf906ead47
Patch
https://github.com/rabbitmq/rabbitmq-server/commit/9f8c39fcf0acbc43080ee7017a62a02832114112
Issue Tracking
https://github.com/rabbitmq/rabbitmq-server/pull/15936
Issue Tracking
https://github.com/rabbitmq/rabbitmq-server/pull/15940
Release Notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
Exploit
https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-36m6-588r-vqcw
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