VulnerabilityAnalyzed

CVE-2026-66080

RabbitMQ is a messaging and streaming broker.

MEDIUM 5.9EPSS 0.32%

Does this matter?

Lower severity and a low EPSS score (0.32%). Track it; it rarely justifies an emergency change on its own.

Description

RabbitMQ is a messaging and streaming broker. Prior to versions 4.1.11, 4.2.6, and 4.3.0, validate_partitions only checks that the requested partition count is at least 1, with no upper bound. A large count such as lists:seq(0, 500000000) allocates roughly 8GB. Preconditions include The rabbitmq_stream_management plugin must be enabled. The caller needs the management tag and access to the target vhost.. This issue is fixed in versions 4.1.11, 4.2.6, and 4.3.0.

CVSS 4.0: 5.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.32% probability · 24th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-770
Affected: broadcom/rabbitmq server
Source: security-advisories@github.com

EPSS trend

EPSS moved from 0.3% on 24 September 2026 to 0.3% on 26 October 2026.

References

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6Release Notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0Release Notes
https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-wg79-5449-m728Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.