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TI-2026-32718 Aliases CVE-2026-44838

RabbitMQ MQTT Topic Permission Authorization Bypass

Priority LOW 23CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-863.

Summary

RabbitMQ is a messaging and streaming broker. From 4.2.0 to before 4.2.4, RabbitMQ's MQTT plugin allows for topic-level authorization using regular expressions with variable substitution. Administrators can create patterns such as ^{client_id}-sensors$ to restrict user access to topics that include their client ID. However, the client_id is provided by the user in the MQTT CONNECT packet and is inserted into the regex pattern without escaping special regex characters. This flaw enables an authenticated MQTT user to inject regex operators to bypass authorization. This vulnerability is fixed in 4.2.4 and 4.3.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00203 10th percentileScored 2026-11-07
Fix Fixed rabbitmq-server (rabbitmq): 4.2.4Red Hat: 2 advisories

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

VendorProductAffected versionsFixed inStatusSource
rabbitmqrabbitmq-server4.2.0 to before 4.2.44.2.4Patch availableCNA
  • rabbitmq-server Vendorrabbitmq Affected 4.2.0 to before 4.2.4 Fixed in 4.2.4 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:*4.2.0 to before 4.2.4VulnerableBroadcom
  • cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* Versions 4.2.0 to before 4.2.4 Vulnerable ·Broadcom

Remediation

  • Fix · CNA rabbitmq-server (rabbitmq) Fixed in 4.2.4

Red Hat 2 advisories

  • RHSA-2026:45128 Released 2026-07-24 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images rabbitmq-server4-3-main@aarch64, rabbitmq-server4-3-main@src, rabbitmq-server4-3-main@x86_64
  • RHSA-2026:42387 Released 2026-07-21 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images rabbitmq-server4-2-main@aarch64, rabbitmq-server4-2-main@src, rabbitmq-server4-2-main@x86_64

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Hardened ImagesFixed RHSA-2026:42387, RHSA-2026:45128
Not affected: 3 products
  • Red Hat OpenStack Platform 16.2
  • Red Hat OpenStack Platform 17.1
  • Red Hat OpenStack Platform 18.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-44838

References

Advisory 1

  • 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
See all 100 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences