HighCVE-2026-66070

    RabbitMQ: CORS * reflects Origin with Allow-Credentials (CVE-2026-66070)

    Published Last modified Sources: Ubuntu, Red Hat, CVE.org, OSV, Msrc Update Guide

    What is affected, what to do

    A flaw was found in RabbitMQ. When the management plugin is configured with a wildcard Cross-Origin Resource Sharing (CORS) origin, it incorrectly reflects the attacker's origin and allows credentials.

    Update rabbitmq_server to version 4.1.13.

    Affected
    • Rabbitmq-server gte 3.13.0, < 3.13.17..*

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    8.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    8.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Ubuntu, Red Hat, CVE.org, OSV, Msrc Update Guide

    0.4 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 31.1

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    80.45 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    8.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.8
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.6
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

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    0.4 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    31.1
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 24 September 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-942

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    A flaw was found in RabbitMQ. When the management plugin is configured with a wildcard Cross-Origin Resource Sharing (CORS) origin, it incorrectly reflects the attacker's origin and allows credentials. This vulnerability enables a malicious web page to leverage a signed-in administrator's cached credentials. Consequently, an attacker can issue authenticated requests to the management API, potentially leading to unauthorized actions.

    Source: Ubuntu Security Notices, redhat_csaf, NVD (NIST), cvelistv5, OSV (Open Source Vulnerabilities), Microsoft Security Update Guide

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    rabbitmqrabbitmq-server
    • ≥ 3.13.0, < 3.13.17
    • —
    broadcomrabbitmq_server
    • 4.1.0 – < 4.1.13
    • 3.13.0 – < 3.13.17
    • 4.0.0 – < 4.0.22
    • 4.2.0 – < 4.2.6
    • 4.1.13
    • 3.13.17
    • 4.0.22
    • 4.2.6
    Distribution and container packages (4)

    Downstream packages (e.g. Bitnami, Debian, Ubuntu, Red Hat). Versions refer to the distribution, not the vendor.

    Distribution and container packages
    Affected versionsFixed in
    bitnamirabbitmq
    • 4.2.0
    • 4.1.0
    • 3.13.0
    • 4.0.0
    • 4.2.6
    • 4.1.13
    • 3.13.17
    • 4.0.22

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxubunturabbitmq-serverbionic
    Linuxubunturabbitmq-serverfocal
    Linuxubunturabbitmq-serverjammy
    Linuxubunturabbitmq-servernoble
    Linuxubunturabbitmq-serverresolute
    Linuxubunturabbitmq-serverxenial

    Weakness classes (CWE)

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

      Variant

      The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate.

      Entry at MITRE CWE-942

    References & sources

    • github.comrabbitmq/rabbitmq-server/security/advisories/GHSA-p3hp-v9wh-ghm7x_refsource_CONFIRM, Vendor advisory, advisory
    • github.comrabbitmq/rabbitmq-server/releases/tag/v4.2.6x_refsource_MISC, Release notes, article
    • NVD (NIST)vuln/detail/CVE-2026-66070web

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Initial analysis by NVDNVD

      Newly listed as affected:
      • Broadcom RabbitMQ (4.2.0 – before 4.2.6; 4.0.0 – before 4.0.22; 4.1.0 – before 4.1.13; 3.13.0 – before 3.13.17)

      CVSS V3.1: AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
      Product configurationadded
      —
      OR *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (excluding) 4.2.6 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.0.0 up to (excluding) 4.0.22 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 4.1.0 up to (excluding) 4.1.13 *cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:* versions from (including) 3.13.0 up to (excluding) 3.13.17
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6 Types: Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-p3hp-v9wh-ghm7 Types: Vendor Advisory

      Source identifier: nvd@nist.gov

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-66070","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-09-24T14:16:50.638390Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    3. ReceivedGitHub

      CVSS V4.0: AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

      Weakness type: CWE-942

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      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.
      CVSSadded
      —
      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
      Weakness type (CWE)added
      —
      CWE-942
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/66xxx/CVE-2026-66070.json">CVE-2026-66070</a>
      Referenceadded
      —
      https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
      Referenceadded
      —
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-p3hp-v9wh-ghm7

      Source identifier: security-advisories@github.com

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