RabbitMQ: Non-RFC-conformant cookie name when clearing the auth-mechanism preference
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- 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.
Summary
RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.8 and 4.3.2, get_auth_mechanism/1 used term_to_binary/1 on the strict_auth_mechanism or preferred_auth_mechanism atom when clearing the corresponding cookie, producing a non-ASCII cookie name that violates RFC 6265 and can prevent the browser from deleting the preference. The issue is not directly exploitable for code execution or data exfiltration; its security relevance is limited to stale authentication-mechanism preferences persisting across logout and login cycles. This issue is fixed in versions 4.2.8 and 4.3.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- 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 4.2.8, 4.3.2
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: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Hardened Images | Affected | No fix yet: Fix deferred |
| 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-2026-67234
- 2026-10-18 Fix available: RHSA-2026:67552 · Red Hat
- 2026-10-18 Fix available: Red Hat Hardened Images · Red Hat
- 2026-10-18 CVSS score added · Red Hat
- 2026-10-20 CVSS score added · NVD
References
Patch 4
- https://github.com/rabbitmq/rabbitmq-server/commit/149cb59d618cefa83c6deb02dbbb1e8a7a2bc968
- https://github.com/rabbitmq/rabbitmq-server/commit/baac0aaf170efeb4f124ee36b8417274fa8dcc1a
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2
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-2026-67234 · CVE Program
- CVE-2026-67234 · NVD
- FIRST EPSS
- CVE-2026-67234 · Red Hat security data · CC BY 4.0
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