What’s Vulnerable › Vulnerabilities

CVE-2026-57220: RabbitMQ: Stream listener does not enforce configured frame-size limit during authentication, permitting unauth'd mem-exhaust DoS

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-10 · updated 2026-10-25
• Weakness: CWE-770

Description

RabbitMQ is a messaging and streaming broker. Prior to 4.2.6, the RabbitMQ stream listener does not enforce the configured stream frame-size limit while assembling frames during authentication and before Tune negotiation, allowing an unauthenticated remote client to declare oversized frame lengths and consume broker memory in rabbit_stream_core. This issue is fixed in version 4.2.6.

Affected products

• rabbitmq-server: from 4.2.0 before 4.2.6 — fixed in 4.2.6

How to fix

Upgrade to a fixed version: rabbitmq-server 4.2.6. Check the vendor advisory for mitigations.

References

• https://github.com/rabbitmq/rabbitmq-server/commit/595ec28fa1621b1f2c28124e4e0466a8ad963547
• https://github.com/rabbitmq/rabbitmq-server/commit/773a49c4921e8be990262a2d609c35916825679e
• https://github.com/rabbitmq/rabbitmq-server/pull/16171
• https://github.com/rabbitmq/rabbitmq-server/pull/16173
• https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
• https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-f364-87q5-j35q
• https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-f364-87q5-j35q

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