HighCVE-2026-33247

    NATS credentials are exposed in monitoring port via command-line argv (CVE-2026-33247)

    Published Last modified Sources: Red Hat, OSV, CVE.org, BSI

    What is affected, what to do

    A flaw was found in NATS-Server. If the NATS-Server is configured with static credentials provided through command-line arguments (argv) and the monitoring port is enabled, a remote attacker with access to the monitoring port can view these credentials.

    Update Nats-io Nats-server to version 2.11.15.

    Affected
    • Nats-io Nats-server gte 2.12.0-RC.1, < 2.12.6..*
    • Nats-io Nats-server lt *..2.11.15
    Fixed in
    • Nats-io Nats-server 2.11.15

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

    Metrics

    7.4

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.4

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Red Hat, OSV, CVE.org, BSI

    0.4 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 37.2

    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
    63.55 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
    7.4 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
    7.4
    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“.

    Read in glossary
    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
    37.2
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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 26 March 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-215

    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 NATS-Server. If the NATS-Server is configured with static credentials provided through command-line arguments (argv) and the monitoring port is enabled, a remote attacker with access to the monitoring port can view these credentials. The /debug/vars endpoint on the monitoring port exposes an unredacted copy of the command-line arguments, leading to information disclosure of sensitive authentication details.

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

    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
    nats-ionats-server
    • ≥ 2.12.0-RC.1, < 2.12.6
    • < 2.11.15
    • —
    • 2.11.15
    linuxfoundationnats-server
    • < 2.11.15
    • 2.12.0 – < 2.12.6
    • 2.11.15
    • 2.12.6
    Open SourceNATS Server
    • < 2.11.15
    • < 2.12.6
    • 2.11.15
    • 2.12.6
    gogithub.com/nats-io/nats-server/v2
    • 2.12.0-RC.1
    • —
    • —
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-215Insertion of Sensitive Information Into Debugging Code

      Base

      The product inserts sensitive information into debugging code, which could expose this information if the debugging code is not disabled in production.

      Entry at MITRE CWE-215

    References & sources

    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. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/33xxx/CVE-2026-33247.json">CVE-2026-33247</a>

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    2. Record modifiedGitHub

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://advisories.nats.io/CVE/secnote-2026-14.txt
      Referenceadded
      —
      https://github.com/nats-io/nats-server/security/advisories/GHSA-x6g4-f6q3-fqvv
      Referenceremoved
      https://advisories.nats.io/CVE/secnote-2026-14.txt
      —
      Referenceremoved
      https://github.com/nats-io/nats-server/security/advisories/GHSA-x6g4-f6q3-fqvv
      —
      Reference typeremoved
      https://advisories.nats.io/CVE/secnote-2026-14.txt Types: Mitigation, Vendor Advisory
      —
      Reference typeremoved
      https://github.com/nats-io/nats-server/security/advisories/GHSA-x6g4-f6q3-fqvv Types: Mitigation, Vendor Advisory
      —

      Source identifier: security-advisories@github.com

    3. Record modifiedRed Hat ADP

      Show 13 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/33xxx/CVE-2026-33247.json">CVE-2026-33247</a>
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:21769
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:22347
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:23345
      Referenceadded
      —
      https://access.redhat.com/security/cve/CVE-2026-33247
      Referenceadded
      —
      https://bugzilla.redhat.com/show_bug.cgi?id=2451486
      Referenceadded
      —
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33247.json
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:21769
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:22347
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:23345
      —
      Referenceremoved
      https://access.redhat.com/security/cve/CVE-2026-33247
      —
      Referenceremoved
      https://bugzilla.redhat.com/show_bug.cgi?id=2451486
      —
      Referenceremoved
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33247.json
      —

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    4. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Multicluster Global Hub 1.5.4, Multicluster Global Hub 1.6.5, Red Hat multicluster global hub 1.4.2 (+1)
      Multicluster Global Hub 1.5.6, Red Hat multicluster global hub 1.4.2, Red Hat multicluster global hub 1.6.0 (+1)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    5. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Multicluster Global Hub 1.5.4, Red Hat multicluster global hub 1.4.4, Red Hat multicluster global hub 1.6.0 (+1)
      Multicluster Global Hub 1.4.5, Red Hat multicluster global hub 1.5.0, Red Hat multicluster global hub 1.6.0 (+1)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    Show 3 older changes

    1. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Multicluster Global Hub 1.4.5, Multicluster Global Hub 1.6.2, Red Hat multicluster global hub 1.5.2 (+1)
      Multicluster Global Hub 1.5.4, Red Hat multicluster global hub 1.4.4, Red Hat multicluster global hub 1.6.0 (+1)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    2. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Multicluster Global Hub 1.5.4, Multicluster Global Hub 1.6.2, Red Hat multicluster global hub 1.4.3 (+1)
      Multicluster Global Hub 1.4.5, Multicluster Global Hub 1.6.2, Red Hat multicluster global hub 1.5.2 (+1)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    3. Record modifiedRed Hat ADP

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Multicluster Global Hub 1.4.5, Multicluster Global Hub 1.5.4, Multicluster Global Hub 1.6.2 (+1)
      Multicluster Global Hub 1.5.4, Multicluster Global Hub 1.6.2, Red Hat multicluster global hub 1.4.3 (+1)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

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