CVE-2026-66074

What it is

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, match_value/3 passes the user-supplied ?name= regular expression to re:run with no match_limit option, and executes it once per resource in the result set. OTP's default 10M match_limit caps each call at roughly 100-200ms, but the regex runs once per resource in the result set. With a large set, for example 5000 queues at 150ms each, a single request consumes 12 or more minutes of CPU. Parallel requests saturate the schedulers. The use_regex=true option is a supported feature on list endpoints, so this path is reachable through normal API use. Preconditions include Any user with the management tag can exploit this.. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of service disruption.

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 21:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-19 20:37 UTC Last updatedMost recent change to the record

Details

Published

2026-09-23 21:16 UTC

Last modified

2026-10-19 20:37 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-1333

Record status

Analyzed

Affected

• Broadcom Rabbitmq Server < 3.13.15
• Broadcom Rabbitmq Server < 4.0.20
• Broadcom Rabbitmq Server < 4.1.11
• Broadcom Rabbitmq Server < 4.2.6

Attack profile CVSS 4.0 · 6.0

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

Low

User interaction

None

Confidentiality

None

Integrity

None

Availability

High