XSS in Broadcom Rabbitmq Server

CVE-2026-67239

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.18 and 4.0.23 and 4.1.14 and 4.2.9 and 4.3.3, Stored XSS via TLS peer-certificate DN in stream-management UI (sibling of V-11). lines 102/106/110 render peercertsubject / peercertissuer with raw <%= %> and no fmtstring(). RFC4514 backslash-escaping of </> is HTML-inert and bypassable (<img ... //>). Requires non-default config: a stream TLS listener with verifypeer and an attacker-obtainable trusted cert with a malicious Same as the connection.ejs finding, against operators viewing the stream-connection detail rabbitmqstream + rabbitmqstreammanagement enabled with a TLS listener using verifypeer Attacker can obtain a certificate signed by a CA the listener trusts, with attacker-chosen DN An operator views the. This issue is fixed in versions 3.13.18 and 4.0.23 and 4.1.14 and 4.2.9 and 4.3.3.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (4.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.6% 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-2026-67239: held from 0.003 to 0.002.

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-67239?
CVE-2026-67239 is a medium-severity vulnerability in Broadcom Rabbitmq Server, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-09-25.
How severe is CVE-2026-67239?
Medium severity. CVSS v3 base score is 5.4 out of 10.