RabbitMQ: AMQP 0-9-1 body assembly never validates accumulated size
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.
CVE-2026-67235
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-67235
rabbitmq-server
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "rabbitmq",
"product": "rabbitmq-server",
"versions": [
{
"status": "affected",
"version": ">= 4.2.0, < 4.2.6"
},
{
"status": "affected",
"version": ">= 4.1.0, < 4.1.11"
},
{
"status": "affected",
"version": ">= 4.0.0, < 4.0.20"
},
{
"status": "affected",
"version": ">= 3.13.0, < 3.13.15"
}
]
}
]- Related CVEs
- CVE-2026-67235
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #1767 · Revision 1
- Added to Heist Feed
- Publisher date