OpenStack oslo.messaging does not verify RabbitMQ broker hostname during TLS handshake
An issue was discovered in OpenStack oslo.messaging 1.0.0 through 17.3.0. The oslo.messaging RabbitMQ driver does not 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. Any certificate signed by the deployment CA is accepted regardless of hostname, allowing 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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | oslo-messaging | >= 1.0.0, <= 17.3.0 | no fix |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-44393
- https://access.redhat.com/security/cve/CVE-2026-44393
- https://bugs.launchpad.net/oslo.messaging/+bug/2150316
- https://bugzilla.redhat.com/show_bug.cgi?id=2484835
- https://github.com/openstack/oslo.messaging
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44393.json
- https://wiki.openstack.org/wiki/OSSN/OSSN-0096
- https://pypi.org/project/oslo-messaging
- https://github.com/advisories/GHSA-76qh-xr7q-h39m
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N- Weakness (CWE)
CWE-295, CWE-297- Platform
- Python (PyPI)
- Package
oslo-messaging- Disclosed
- 04.06.2026
- Updated
- 11.10.2026 14:18
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-3492 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-76qh-xr7q-h39m - CC BY 4.0
Vulnerability history: oslo-messaging
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.