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Fencer Vulns
high 8.8

CVE-2026-66070 json

RabbitMQ: CORS * reflects Origin with Allow-Credentials

published 2026-09-23 46 d ago modified 2026-10-20 19 d ago also BIT-rabbitmq-2026-66070 , EUVD-2026-85625 , GHSA-p3hp-v9wh-ghm7

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6, match_origin/1 returned the bare reflected Origin and allowed credentials even when the wildcard "" was configured, so the response echoed the attacker's origin together with Access-Control-Allow-Credentials. The affected code is rabbit_mgmt_cors.erl. When the management plugin is configured with a wildcard CORS origin (cors_allow_origins = ""), the handler reflects the request Origin back in Access-Control-Allow-Origin and also sends Access-Control-Allow-Credentials: true. A malicious web page that a signed-in administrator visits can then use that administrator's cached HTTP Basic credentials to issue authenticated, state-changing requests to the management API. Preconditions include The management plugin is configured with the wildcard cors_allow_origins = "*", which is an explicit operator misconfiguration A target administrator has a cached HTTP Basic-auth session in the browser. This issue is fixed in versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6.

Patch / fix

  • bitnami rabbitmq 3.13.17, 4.0.22, 4.1.13, 4.2.6
  • vmware rabbitmq 3.13.17, 4.0.22, 4.1.13, 4.2.6
  • pivotal_software rabbitmq 3.13.17, 4.0.22, 4.1.13, 4.2.6
  • rabbitmq-server Debian 14 4.3.0-2

debian advisories DEBIAN-CVE-2026-66070

  • 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-2026-66070

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

  • rabbitmq-server Azure Linux 3.0 3.13.7-10

azure linux advisories AZL-105801

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2026-66070 updated cvss 8.1

rabbitmq-server: RabbitMQ: Cross-Origin Resource Sharing (CORS) misconfiguration allows unauthorized actions

  • Red Hat Hardened Images rabbitmq-server4.2 4.2.9-0.2.hum1
    affected: workaround, no fix planned “Replace wildcard CORS with explicit trusted origins and avoid administrator Basic credentials in browsers used for untrusted sites.”
  • Red Hat Hardened Images rabbitmq-server4.3 4.3.6-1.hum1
    fixed: vendor fix “Replace wildcard CORS with explicit trusted origins and avoid administrator Basic credentials in browsers used for untrusted sites.” RHSA-2026:67552
  • Red Hat OpenStack Platform 13 (Queens) rabbitmq-server Red Hat OpenStack Platform 16.2 rabbitmq-server Red Hat OpenStack Platform 17.1 rabbitmq-server Red Hat OpenStack Platform 18.0 rabbitmq-server
    not affected: vulnerable code not present

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
total
Assessed
45 d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 4.0 7.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/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 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
bitnami rabbitmq
>=3.13.0, <3.13.17
>=4.0.0, <4.0.22
>=4.1.0, <4.1.13
>=4.2.0, <4.2.6
3.13.17
4.0.22
4.1.13
4.2.6

Affected products

  • rabbitmq rabbitmq-server

Classification

Weakness
  • CWE-942 Permissive Cross-domain Security Policy with Untrusted Domains

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.