Vulnerability · Published Sep 25, 2026 · Assigned by GitHub_M
CVE-2026-67419RabbitMQ: Consecutive topic wildcards cause combinatorial routing work
High 7.1
In plain English
A high-severity regular-expression denial of service in rabbitmq-server from rabbitmq. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated user who can bind a queue to a topic exchange and publish to it can use consecutive # segments in a binding key to make both topic matchers revisit the same trie-node and routing-key-suffix states without memoization. The matcher materializes duplicate destinations before deduplication, causing combinatorial CPU work and memory pressure that can disrupt routing for all tenants. This vulnerability is fixed in 4.3.5.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | rabbitmq-server | 4.3.6-1 | DEBIAN-CVE-2026-67419 |
| Ubuntu:22.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67419 |
| Ubuntu:24.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67419 |
| Ubuntu:26.04:LTS | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67419 |
| Ubuntu:26.10 | rabbitmq-server | no fix listed | UBUNTU-CVE-2026-67419 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| rabbitmq | rabbitmq-server | < 4.3.5 |
Weakness: CWE-407, CWE-1333 · 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