CVE-2026-44393 OpenStack oslo.messaging does not verify RabbitMQ broker hostname during TLS handshake
Attackers can intercept OpenStack RPC traffic via man-in-the-middle attacks due to missing TLS hostname verification in the RabbitMQ driver.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44393?
CVE-2026-44393 is a high-severity vulnerability in n/a, published on 4 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-44393?
3 open source packages ship an affected version, including oslo-messaging and oslo.messaging.
| Package | Affected | Fixed in |
|---|---|---|
oslo-messaging PyPI | From 1.0.0 to 17.3.0 | None |
oslo-messaging PyPI | From 1.0.0 to 17.3.0 | None |
oslo.messaging PyPI | From 1.0.0 to 17.3.0 | None |
Linux distribution packages (1)
python-oslo.messaging openSUSE:Tumbleweed | All versions | 18.1.0-1.1 |
How do I fix CVE-2026-44393?
Upgrade to a fixed version.
Is CVE-2026-44393 being exploited?
There is no known exploitation of CVE-2026-44393 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-44393, GHSA-76qh-xr7q-h39m, PYSEC-2026-3492, UBUNTU-CVE-2026-44393, openSUSE-SU-2026:10973-1.