Vulnerability in N/a

CVE-2026-44393

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-44393: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44393?
CVE-2026-44393 is a high-severity vulnerability in N/a, classified under Improper Validation of Certificate with Host Mismatch. CVSS score: 7.4/10. Published 2026-06-04.
How severe is CVE-2026-44393?
High severity. CVSS v3 base score is 7.4 out of 10.