# CVE-2026-66074: RabbitMQ: ReDoS via management API ?name= filter

CVE-2026-66074 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-66074 (version 4.3.0-2), released September 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-66074
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0039
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2026
- Weakness: Inefficient Regular Expression Complexity
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66074

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.0-2 | [DEBIAN-CVE-2026-66074](https://patchblox.com/security/data/fix/linux/debian-cve-2026-66074.md) | Sep 25, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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