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Fencer Vulns
medium 6.1

CVE-2026-66077 json

RabbitMQ: Stored XSS via TLS peer-certificate DN in management UI

published 2026-09-23 46 d ago modified 2026-10-20 19 d ago also BIT-rabbitmq-2026-66077 , EUVD-2026-85628 , GHSA-rjcf-35r5-xw38

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6, The management UI uses EJS 1.0 in which <%= ... %> does NOT HTML-escape. connection.ejs:135 renders <%= connection.ssl_details.peer_cert_subject %> (and peer_cert_issuer) directly into the page. The same pattern appears in streamConnection.ejs:102,106,110. The values come from rabbit_ssl:peer_cert_subject/1 which formats the DN as a string without HTML escaping. The verifier corrected the original researcher's claim: this is reachable only when the listener is configured with verify_peer (so the certificate must be signed by a CA in the broker's trust store, not arbitrary self-signed); however, in deployments using mTLS for client authentication, any user who can request a certificate from the organisational CA controls the Subject CN. An attacker who can obtain a TLS client certificate signed by a CA the broker trusts (with verify_peer enabled) can embed JavaScript in the certificate's Subject DN. When any administrator views that connection in the management UI, the script executes in the admin's browser session, allowing full account takeover (create users, export definitions, etc.). The management UI's CSP includes 'unsafe-inline', so inline script execution is not blocked. Preconditions include TLS listener configured with ssl_options.verify = verify_peer Attacker can obtain a CA-signed client certificate with attacker-chosen Subject (e.g. self-service corporate PKI, or rabbitmq_trust_store plugin in use) Administrator views the connection detail page. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.

Patch / fix

  • bitnami rabbitmq 3.13.15, 4.0.20, 4.1.11, 4.2.6
  • vmware rabbitmq 3.13.15, 4.0.20, 4.1.11, 4.2.6
  • pivotal_software rabbitmq 3.13.15, 4.0.20, 4.1.11, 4.2.6
  • rabbitmq-server Debian 14 4.3.0-2

debian advisories DEBIAN-CVE-2026-66077

  • rabbitmq-server Ubuntu 22.04 LTS 3.9.27-0ubuntu0.6
  • rabbitmq-server Ubuntu 24.04 LTS 3.12.1-1ubuntu1.7
  • rabbitmq-server Ubuntu 26.04 LTS 4.0.5-10ubuntu5.2
  • rabbitmq-server Ubuntu Pro 16.04 LTS 3.5.7-1ubuntu0.16.04.4+esm3
  • rabbitmq-server Ubuntu Pro 18.04 LTS 3.6.10-1ubuntu0.5+esm1
  • rabbitmq-server Ubuntu Pro 20.04 LTS 3.8.3-0ubuntu0.3+esm2

ubuntu advisories UBUNTU-CVE-2026-66077

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rabbitmq-server4.3 hummingbird 1 4.3.6-1.hum1

red hat advisories RHSA-2026:67552

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-66077 updated cvss 8.7

RabbitMQ: RabbitMQ: Account takeover via stored Cross-Site Scripting in TLS peer-certificate DN

  • Red Hat Hardened Images rabbitmq-server4.2 4.2.9-0.2.hum1
    affected: no fix planned “Will not fix”
  • Red Hat Hardened Images rabbitmq-server4.3 4.3.6-1.hum1
    fixed: vendor fix RHSA-2026:67552

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
41 d ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
CNA 4.0 7.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
bitnami rabbitmq
>=3.13.0, <3.13.15
>=4.0.0, <4.0.20
>=4.1.0, <4.1.11
>=4.2.0, <4.2.6
3.13.15
4.0.20
4.1.11
4.2.6

Affected products

  • rabbitmq rabbitmq-server

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.