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.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:54757 advisory.

    Red Hat OpenStack Platform provides the facilities for building, deploying and monitoring a private or     public infrastructure-as-a-service (IaaS) cloud running on commonly available physical hardware.

    Security Fix(es):

    * crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate     (CVE-2025-61729)

    * openstack-nova-compute: Arbitrary Host File Overwrite via Unconstrained qemu-img Format Handling in     OpenStack Nova (CVE-2026-24708)

    * pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID (CVE-2026-23490)

    * golang: net/url: Memory exhaustion in query parameter parsing in net/url (CVE-2025-61726)

    * crypto/tls: crypto/tls: Incorrect certificate validation during TLS session resumption (CVE-2025-68121)

    * openstack-glance: OpenStack Glance: Server-Side Request Forgery leading to unauthorized internal network     access (CVE-2026-34881)

    * crypto/x509: Incorrect enforcement of email constraints in crypto/x509 (CVE-2026-27137)

    * net/url: Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679)

    * google.golang.org/grpc/grpc-go: google.golang.org/grpc/authz: gRPC-Go: Authorization bypass due to     improper HTTP/2 path validation (CVE-2026-33186)

    * etcd: etcd: Authorization bypass allows information disclosure and denial of service (CVE-2026-33413)

    * crypto/x509: golang: Go crypto/x509: Denial of Service via inefficient certificate chain validation     (CVE-2026-32281)

    * crypto/x509: golang: Go crypto/x509: Certificate validation bypass due to incorrect DNS constraint     application (CVE-2026-33810)

    * golang: internal/syscall/unix: Root.Chmod can follow symlinks out of the root (CVE-2026-32282)

    * crypto/tls: golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update messages     (CVE-2026-32283)

    * crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building     (CVE-2026-32280)

    * net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME (CVE-2026-33811)

    * golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect     Punycode label processing (CVE-2026-39821)

    * erlang: Erlang OTP public_key: Certificate chain forgery via improper trust chain validation     (CVE-2026-42789)

    * crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries     (CVE-2026-27145)

    * oslo.messaging: openstack: OpenStack oslo.messaging: Man-in-the-middle attack via improper TLS hostname     verification (CVE-2026-44393)

    * erlang: Erlang OTP public_key: Certificate validation bypass allows hostname spoofing (CVE-2026-42790)

    * openstack-keystone: OpenStack Keystone: Unauthorized access and privilege escalation via AWS signature     validation flaw (CVE-2025-65073)

    * OpenStack Keystone: OpenStack Keystone: Unauthorized cross-project access due to improper validation in     EC2 credential creation (CVE-2026-43001)

    * openstack-keystone: OpenStack Keystone: Privilege escalation through EC2 credential creation     (CVE-2026-33551)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-44393)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
335312	RHEL 8 : Red Hat OpenStack Platform 16.2 security advisory (Important) (RHSA-2026:54757)	Nessus	Red Hat Local Security Checks	Local	high
318708	Linux Distros Unpatched Vulnerability : CVE-2026-44393	Nessus	Misc.	Local	high

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