MediumCVE-2026-63336

    RabbitMQ Java client: TrustEverythingTrustManager used by default in useSslProtocol() enables MITM (CVE-2026-63336)

    Published Last modified Sources: BSI, Hersteller, CVE.org, OSV

    What is affected, what to do

    The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, com.rabbitmq.client.ConnectionFactory.useSslProtocol() and ConnectionFactory.useSslProtocol(String) configure com.rabbitmq.client.TrustEverythingTrustManager and leave hostname verification disabled, causing arbitrary server certificates, including self-signed certificates, to be accepted.

    Update Rabbitmq-java-client to version 5.33.0.

    Affected
    • Rabbitmq-java-client lt *..5.33.0
    Fixed in
    • Rabbitmq-java-client 5.33.0

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    Metrics

    5.1

    Priority

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

    Source: Vendor (CNA), CVSS v4

    5.1

    CVSS v4

    Severity Medium on the scale from 0 to 10.

    Source: BSI, Hersteller, CVE.org, OSV

    0.3 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 22.3

    Show all metrics
    Severity
    Medium
    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
    53.91 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
    5.1 Methodology
    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
    5.1
    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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    0.3 %
    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
    22.3
    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
    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-295

    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
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    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

    The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, com.rabbitmq.client.ConnectionFactory.useSslProtocol() and ConnectionFactory.useSslProtocol(String) configure com.rabbitmq.client.TrustEverythingTrustManager and leave hostname verification disabled, causing arbitrary server certificates, including self-signed certificates, to be accepted. A network attacker able to intercept a TLS connection can impersonate the RabbitMQ broker, read protected AMQP traffic, and modify traffic without certificate or hostname validation. The fix changes the production TLS helpers to use the JVM default trust store and enables hostname verification, while retaining an explicitly named development-only no-verification helper. This issue is fixed in version 5.33.0.

    Source: BSI CSAF, BSI WID Portal, GitHub Security Advisories, cvelistv5, NVD (NIST), CVE.org (MITRE), OSV (Open Source Vulnerabilities)

    Affected products

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

    Affected products
    VendorProductAffected versionsFixed in
    rabbitmqrabbitmq-java-client
    • < 5.33.0
    • 5.33.0
    Open SourceRabbitMQ Java Client
    • < 5.33.1
    • 5.33.1
    mavencom.rabbitmq:amqp-client
    • 3.5.5
    • 3.4.3
    • 5.32.0
    • 4.1.1
    • 3.6.4
    • 5.26.0
    • 2.1.1
    • 4.0.0
    • 4.4.2
    • 5.9.0
    • 2.8.2
    • 4.7.0
    • 4.3.0
    • 3.1.1
    • 2.3.0
    • 3.1.0
    • 5.11.0
    • 5.17.0
    • 4.8.1
    • 5.29.0
    • 4.2.2
    • 2.5.1
    • 5.31.0
    • 3.6.1
    • 4.6.0
    • 2.2.0
    • 5.30.0
    • 5.3.0
    • 5.27.0
    • 4.8.0
    • 3.6.3
    • 3.3.0
    • 5.7.0
    • 3.4.0
    • 2.4.1
    • 5.28.0
    • 5.14.3
    • 2.8.5
    • 2.6.0
    • 3.0.2
    • 5.0.0
    • 3.2.4
    • 2.8.3
    • 5.4.0
    • 5.14.1
    • 5.22.0
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    Weakness classes (CWE)

    • CWE-295Improper Certificate Validation

      Base

      The product does not validate, or incorrectly validates, a certificate.

      Entry at MITRE CWE-295

    References & sources

    • github.comrabbitmq/rabbitmq-java-client/security/advisories/GHSA-5m9f-rph…x_refsource_CONFIRM
    • github.comrabbitmq/rabbitmq-java-client/pull/1999x_refsource_MISC
    • github.comrabbitmq/rabbitmq-java-client/pull/2001x_refsource_MISC
    • github.comrabbitmq/rabbitmq-java-client/commit/1e7deb2e6020c9793a81385a53…x_refsource_MISC
    • github.comrabbitmq/rabbitmq-java-client/commit/a4bf571dd368765baaa9cecfae…x_refsource_MISC
    • github.comrabbitmq/rabbitmq-java-client/releases/tag/v5.33.0x_refsource_MISC
    • github.comrabbitmq/rabbitmq-java-clientpackage

    Reanalysis & status changes

    Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

    1. CVE Translatednvd@nist.gov

      • Translation: after Title: rabbitmq-java-client de rabbitmq, Description: La biblioteca cliente Java de RabbitMQ permite a las aplicaciones Java y basadas en JVM conectarse e interactuar con nodos RabbitMQ. Antes de la versión 5.33.0, com.rabbitmq.client.ConnectionFactory.useSslProtocol() y ConnectionFactory.useSslProtocol(String) configuran com.rabbitmq.client.TrustEverythingTrustManager y dejan la verificación de nombre de host deshabilitada, lo que provoca que se acepten certificados de servidor arbitrarios, incluidos los certificados autofirmados. Un atacante de red capaz de interceptar una conexión TLS puede suplantar al intermediario de RabbitMQ, leer tráfico AMQP protegido y modificar el tráfico sin validación de certificado o nombre de host. La solución cambia los ayudantes TLS de producción para usar el almacén de confianza predeterminado de la JVM y habilita la verificación de nombre de host, mientras retiene un ayudante de no verificación explícitamente nombrado y solo para desarrollo. Este problema está solucionado en la versión 5.33.0.
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