CVE-2026-67219: CWE-770: Allocation of Resources Without Limits or Throttling in rabbitmq rabbitmq-server
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, add_binding/3 parses the routing key as an integer weight N and computes ring positions with lists:seq(NextN0, NextN0 + N - 1). validate_binding/2 only checks N >= 1 , no upper bound. The resulting list is stored in the exchange's Khepri record, replicated cluster-wide, and reloaded on restart. A user with write permission on a consistent-hash exchange and read on a queue can create a binding whose routing key (the hash-ring weight) is an arbitrarily large integer. The broker allocates a list of that many integers via lists:seq/2 and persists it to Khepri across all cluster nodes , a single binding with weight 100000000 allocates ~800 MB on every node and survives restarts. Preconditions include rabbitmq_consistent_hash_exchange plugin enabled write permission on a consistent-hash exchange + read on a queue (standard binding perms). This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.
AI Analysis
Technical Summary
The vulnerability exists in the add_binding/3 function of rabbitmq-server where the routing key is parsed as an integer weight N without an upper bound check. The function lists:seq(NextN0, NextN0 + N - 1) generates a list of size N, which is stored and replicated cluster-wide. A malicious user with appropriate permissions can specify a very large N, causing large memory allocations (~800 MB for weight 100,000,000) on all cluster nodes. This can degrade performance or cause denial of service. The issue requires the rabbitmq_consistent_hash_exchange plugin to be enabled and specific permissions. Fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.
Potential Impact
An attacker with write permission on a consistent-hash exchange and read permission on a queue can cause the broker to allocate excessive memory on all cluster nodes by creating a binding with a very large routing key weight. This can lead to resource exhaustion, degraded performance, and potential denial of service. The large allocation persists across restarts due to replication and persistence in the Khepri record.
Mitigation Recommendations
This vulnerability is fixed in rabbitmq-server versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0. Users should upgrade to one of these fixed versions to remediate the issue. No other mitigation or temporary workaround is indicated by the vendor advisory.
CVE-2026-67219: CWE-770: Allocation of Resources Without Limits or Throttling in rabbitmq rabbitmq-server
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, add_binding/3 parses the routing key as an integer weight N and computes ring positions with lists:seq(NextN0, NextN0 + N - 1). validate_binding/2 only checks N >= 1 , no upper bound. The resulting list is stored in the exchange's Khepri record, replicated cluster-wide, and reloaded on restart. A user with write permission on a consistent-hash exchange and read on a queue can create a binding whose routing key (the hash-ring weight) is an arbitrarily large integer. The broker allocates a list of that many integers via lists:seq/2 and persists it to Khepri across all cluster nodes , a single binding with weight 100000000 allocates ~800 MB on every node and survives restarts. Preconditions include rabbitmq_consistent_hash_exchange plugin enabled write permission on a consistent-hash exchange + read on a queue (standard binding perms). This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.
CVSS v4.0
Score 6.0medium
Affected software
rabbitmq
rabbitmq-server
pkg:github/rabbitmq/rabbitmq-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability exists in the add_binding/3 function of rabbitmq-server where the routing key is parsed as an integer weight N without an upper bound check. The function lists:seq(NextN0, NextN0 + N - 1) generates a list of size N, which is stored and replicated cluster-wide. A malicious user with appropriate permissions can specify a very large N, causing large memory allocations (~800 MB for weight 100,000,000) on all cluster nodes. This can degrade performance or cause denial of service. The issue requires the rabbitmq_consistent_hash_exchange plugin to be enabled and specific permissions. Fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.
Potential Impact
An attacker with write permission on a consistent-hash exchange and read permission on a queue can cause the broker to allocate excessive memory on all cluster nodes by creating a binding with a very large routing key weight. This can lead to resource exhaustion, degraded performance, and potential denial of service. The large allocation persists across restarts due to replication and persistence in the Khepri record.
Mitigation Recommendations
This vulnerability is fixed in rabbitmq-server versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0. Users should upgrade to one of these fixed versions to remediate the issue. No other mitigation or temporary workaround is indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-28T19:50:39.437Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ab43b0df7a7c54106517560
Added to database: 09/23/2026, 20:48:13 UTC
Last enriched: 09/23/2026, 21:03:09 UTC
Last updated: 09/24/2026, 01:57:04 UTC
Views: 9
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