Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M
CVE-2026-67235RabbitMQ: AMQP 0-9-1 body assembly never validates accumulated size
High 7.1
In plain English
A high-severity resource allocation without limits in rabbitmq-server from rabbitmq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
RabbitMQ is a messaging and streaming broker. Prior to versions 4.3.0, 4.2.6, 4.1.11, 4.0.20, and 3.13.15, The content-header BodySize (a uint64) was stored without validation against max_message_size. The size check ran only when assembly completed. By declaring body_size = 2^63-1 and then streaming fragments, a client ensured that check_msg_size never fired, so the accumulated body size went unbounded. A reader process accumulates memory until the memory alarm fires, degrading all publishers cluster-wide, or until the node runs out of memory. The memory alarm provides only partial mitigation, since it is reactive rather than preventive. AMQP 0-9-1 is the most widely used protocol, and any publisher can trigger this condition. Preconditions include Any authenticated AMQP 0-9-1 client with publish permission can exploit this.. This issue is fixed in versions 4.3.0, 4.2.6, 4.1.11, 4.0.20, and 3.13.15.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | rabbitmq-server | no fix listed | DEBIAN-CVE-2026-67235 |
| Debian:13 | rabbitmq-server | no fix listed | DEBIAN-CVE-2026-67235 |
| Debian:14 | rabbitmq-server | 4.3.0-2 | DEBIAN-CVE-2026-67235 |
| Ubuntu:22.04:LTS | rabbitmq-server | 3.9.27-0ubuntu0.6 | UBUNTU-CVE-2026-67235 |
| Ubuntu:22.04:LTS | rabbitmq-server | 3.9.27-0ubuntu0.6 | USN-8933-1 |
| Ubuntu:24.04:LTS | rabbitmq-server | 3.12.1-1ubuntu1.7 | USN-8933-1 |
| Ubuntu:24.04:LTS | rabbitmq-server | 3.12.1-1ubuntu1.7 | UBUNTU-CVE-2026-67235 |
| Ubuntu:26.04:LTS | rabbitmq-server | 4.0.5-10ubuntu5.2 | USN-8933-1 |
| Ubuntu:26.04:LTS | rabbitmq-server | 4.0.5-10ubuntu5.2 | UBUNTU-CVE-2026-67235 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| rabbitmq | rabbitmq-server | >= 4.2.0, < 4.2.6>= 4.1.0, < 4.1.11>= 4.0.0, < 4.0.20>= 3.13.0, < 3.13.15 |
Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q8g2-pc7m-m3jw x_refsource_CONFIRM
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6 x_refsource_MISC
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0 x_refsource_MISC