RabbitMQ: Consecutive topic wildcards cause combinatorial routing work
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 fixed, 5 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-1333.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA rabbitmq-server (rabbitmq) Fixed in 4.3.5
Red Hat 1 advisory
- RHSA-2026:67552 Released 2026-09-15 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images rabbitmq-server4.3-4.3.6-1.hum1@aarch64, rabbitmq-server4.3-4.3.6-1.hum1@src, rabbitmq-server4.3-4.3.6-1.hum1@x86_64
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Hardened Images | Affected | No fix planned: Will not fix |
| Red Hat OpenStack Platform 13 (Queens) | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 16.2 | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 17.1 | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 18.0 | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:67552 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-67419
- 2026-10-09 Fix available: RHSA-2026:67552 · Red Hat
- 2026-10-09 Fix available: Red Hat Hardened Images · Red Hat
- 2026-10-09 CVSS score added · Red Hat
- 2026-10-16 CVSS score added · NVD
References
More rabbitmq vulnerabilities
- TI-2026-41154 Improper authentication in rabbitmq-server CVSS 3.1CRITICAL 10.0
- TI-2026-41149 RabbitMQ: UNC SSRF affecting the management UI on Windows CVSS 3.1CRITICAL 10.0
- TI-2026-41158 Resource allocation without limits in rabbitmq-server CVSS 3.1HIGH 7.5
- TI-2026-47695 RabbitMQ: OAuth2 Client Secret Exposed via Unauthenticated JavaScript Endpoint CVSS 4.0HIGH 8.2
- TI-2026-47694 RabbitMQ: JWKS Fetch Ignores HTTP Response Status Code - Signing Key Destruction Causes Authentication DoS CVSS 4.0HIGH 8.2
- TI-2026-45167 RabbitMQ Java client: Unvalidated Class.forName in JSON-RPC ProcedureDescription enables arbitrary class loading CVSS 4.0HIGH 7.5
Sources
- CVE-2026-67419 · CVE Program
- CVE-2026-67419 · NVD
- FIRST EPSS
- CVE-2026-67419 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences