CVE-2026-67421

CVE-2026-67421 is a medium-severity vulnerability in Broadcom Rabbitmq Server with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

Description

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5, RabbitMQ Management rendered an AMQP authorization-error reason containing an attacker-controlled queue name as HTML when the OAuth management UI was enabled. Exploitation requires an attacker with queue configure permission, a management administrator who can see but cannot read that queue, and the administrator clicking Get Message(s). A queue name containing a base element can then retarget the automatic relative refresh because the Content Security Policy omits base-uri and connect-src, and an attacker endpoint that permits the management origin through CORS can receive the victim's Authorization header. This issue is fixed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5.

Frequently asked questions

What is CVE-2026-67421?
RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5, RabbitMQ Management rendered an AMQP authorization-error reason containing an attacker-controlled queue name as HTML when the OAuth management UI was enabled. Exploitation requires an attacker with queue configure permission, a management administrator who can see but cannot read that queue, and the administrator clicking Get Message(s). A queue name containing a base element can then retarget the automatic relative refresh because the Content Security Policy omits base-uri and connect-src, and an attacker endpoint that permits the management origin through CORS can receive the victim's Authorization header. This issue is fixed in versions 3.13.19, 4.0.24, 4.1.15, 4.2.10, and 4.3.5.
How severe is CVE-2026-67421?
CVE-2026-67421 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-67421 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-67421?
CVE-2026-67421 affects Broadcom Rabbitmq Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-67421?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-67421 published?
CVE-2026-67421 was published on 2026-09-25 and last updated on 2026-10-06.

References

Affected products (1)

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