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CVE-2026-44393 OpenStack CVE debrief

CVE-2026-44393 is a HIGH severity vulnerability in OpenStack oslo.messaging 1.0.0 through 17.3.0. The RabbitMQ driver fails to perform TLS hostname verification when connecting to the message broker. When `ssl_ca_file` is configured, the driver enables certificate chain validation but does not pass the expected broker hostname into the underlying TLS stack. This allows an attacker who can intercept control-plane traffic to impersonate the RabbitMQ broker and perform a man-in-the-middle attack on RPC and notification traffic. All OpenStack services using oslo.messaging with RabbitMQ over TLS are affected.

Vendor
OpenStack
Product
oslo.messaging
CVSS
HIGH 7.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-04
Original CVE updated
2026-08-27
Advisory published
2026-06-04
Advisory updated
2026-08-27

Who should care

Users of OpenStack oslo.messaging with RabbitMQ over TLS should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The oslo.messaging RabbitMQ driver does not perform TLS hostname verification when connecting to the message broker. This allows an attacker to impersonate the RabbitMQ broker and perform a man-in-the-middle attack on RPC and notification traffic.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches or updates to oslo.messaging to enable proper TLS hostname verification.
  • Review and update OpenStack services using oslo.messaging with RabbitMQ over TLS to ensure they are not vulnerable.

Evidence notes

The CVE-2026-44393 record and associated references provide evidence for this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-44393 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-44393

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-44393 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-44393

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.