CVE-2026-66070

What it is

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6, match_origin/1 returned the bare reflected Origin and allowed credentials even when the wildcard "" was configured, so the response echoed the attacker's origin together with Access-Control-Allow-Credentials. The affected code is rabbit_mgmt_cors.erl. When the management plugin is configured with a wildcard CORS origin (cors_allow_origins = ""), the handler reflects the request Origin back in Access-Control-Allow-Origin and also sends Access-Control-Allow-Credentials: true. A malicious web page that a signed-in administrator visits can then use that administrator's cached HTTP Basic credentials to issue authenticated, state-changing requests to the management API. Preconditions include The management plugin is configured with the wildcard cors_allow_origins = "*", which is an explicit operator misconfiguration A target administrator has a cached HTTP Basic-auth session in the browser. This issue is fixed in versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-23 20:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-19 20:36 UTC Last updatedMost recent change to the record

Details

Published

2026-09-23 20:17 UTC

Last modified

2026-10-19 20:36 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-942

Record status

Analyzed

Affected

• Broadcom Rabbitmq Server < 3.13.17
• Broadcom Rabbitmq Server < 4.0.22
• Broadcom Rabbitmq Server < 4.1.13
• Broadcom Rabbitmq Server < 4.2.6

Attack profile CVSS 4.0 · 7.6

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

Passive

Confidentiality

High

Integrity

High

Availability

None