HighCVE-2026-14457

    RPK Server Signature Algorithm Selection Can Dereference a Missing Certificate (CVE-2026-14457)

    Published Last modified Sources: Red Hat, SUSE, Debian, Ubuntu, CVE.org, Msrc Update Guide, BSI

    What is affected, what to do

    A flaw was found in OpenSSL. In a server or client configuration with RFC7250 Raw Public Keys (RPKs) enabled, where only the private key (with no certificate) is configured, a NULL pointer dereference may occur when the remote peer solicits raw public keys and also sends the typically omitted "signature_algorithms_cert" TLS extension.

    Update OpenSSL to version 4.0.2, OpenSSL to version 3.6.4, OpenSSL to version 3.5.8.

    Affected
    • OpenSSL lt 4.0.0..4.0.2
    • OpenSSL lt 3.6.0..3.6.4
    • OpenSSL lt 3.5.0..3.5.8
    • OpenSSL lt 3.4.0..3.4.7
    Fixed in
    • OpenSSL 4.0.2
    • OpenSSL 3.6.4
    • OpenSSL 3.5.8
    • OpenSSL 3.4.7

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

    Metrics

    7.5

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Red Hat, SUSE, Debian, Ubuntu, CVE.org, Msrc Update Guide, BSI

    1.2 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 67.3

    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
    97.99 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
    7.5 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
    7.5
    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
    1.2 %
    Moderate — model estimates 1-10% 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
    67.3
    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 · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 25 August 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-476

    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 OpenSSL. In a server or client configuration with RFC7250 Raw Public Keys (RPKs) enabled, where only the private key (with no certificate) is configured, a NULL pointer dereference may occur when the remote peer solicits raw public keys and also sends the typically omitted "signature_algorithms_cert" TLS extension. This issue results in a denial of service.

    Source: redhat_csaf, suse_csaf, Debian Security Advisories, Ubuntu Security Notices, NVD (NIST), cvelistv5, Microsoft Security Update Guide, BSI WID Portal, BSI CSAF

    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
    OpenSSLOpenSSL
    • 3.6.0 – < 3.6.4
    • 3.4.0 – < 3.4.7
    • 4.0.0 – < 4.0.2
    • 3.5.0 – < 3.5.8
    • 3.6.4
    • 3.4.7
    • 4.0.2
    • 3.5.8
    opensslopenssl
    • 3.5.0 – < 3.5.8
    • 3.4.0 – < 3.4.7
    • 4.0.0 – < 4.0.2
    • 3.6.0 – < 3.6.4
    • 3.5.8
    • 3.4.7
    • 4.0.2
    • 3.6.4
    FreeBSD ProjectFreeBSD OS
    • < 15.1-STABLE
    • < 14.4-STABLE
    • < 15.0-RELEASE-p13
    • < 14.4-RELEASE-p9
    • < 15.1-RELEASE-p3
    • 15.1-STABLE
    • 14.4-STABLE
    • 15.0-RELEASE-p13
    • 14.4-RELEASE-p9
    • 15.1-RELEASE-p3
    MeinbergLANTIME
    • < V7.10.016
    • V7.10.016
    Open SourceOpenSSL
    • < 3.4.7
    • < 4.0.2
    • < 3.5.8
    • < 3.6.4
    • < 3.0.22
    • < 1.1.1zi
    • < 1.0.2zr
    • 3.4.7
    • 4.0.2
    • 3.5.8
    • 3.6.4
    • 3.0.22
    • 1.1.1zi
    • 1.0.2zr

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianopenssltrixie
    Linuxubuntuopenssljammy
    Linuxubuntuopensslnoble
    Linuxubuntuopensslresolute

    Weakness classes (CWE)

    • CWE-476NULL Pointer Dereference

      Base

      The product dereferences a pointer that it expects to be valid but is NULL.

      Entry at MITRE CWE-476

    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. Initial analysis by NVDNVD

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationadded
      —
      OR *cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* versions from (including) 3.5.0 up to (excluding) 3.5.8 *cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* versions from (including) 3.6.0 up to (excluding) 3.6.4 *cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* versions from (including) 4.0.0 up to (excluding) 4.0.2 *cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* versions from (including) 3.4.0 up to (excluding) 3.4.7
      Reference typeadded
      —
      OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/1e8c398db67404babd3e5af999bb6bd86f720c76 Types: Patch
      Reference typeadded
      —
      OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/581aaa0f0a35d214740f0fe1f5283ec41f1212e1 Types: Patch
      Reference typeadded
      —
      OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/d0af20478688a6aa2f59d61caa3f82136b181d7f Types: Patch
      Reference typeadded
      —
      OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/dad836b071da6579510c968615848ba03cac593b Types: Patch
      Reference typeadded
      —
      OpenSSL Software Foundation: https://openssl-library.org/news/secadv/20260825.txt Types: Vendor Advisory

      Source identifier: nvd@nist.gov

    2. Receivedopenssl.org

      Show 8 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      OpenSSL
      Descriptionadded
      —
      Issue summary: In a server or client configuration with RFC7250 Raw Public Keys (RPKs) enabled, and only the private key (with no associated certificate) configured locally, a NULL pointer dereference may occur when the remote peer solicits raw public keys and also sends the typically omitted "signature_algorithms_cert" TLS extension. Impact summary: The impact is limited to a possible Denial of Service as a result of an application abort, no data disclosure or remote command execution are possible. CWE: CWE-476: NULL Pointer Dereference Description: While a passing comment in sample code in the documentation suggests that key-only RPK configurations are supported, the best-practice RPK configuration is to always configure a corresponding certificate (possibly self-signed or signed by any convenient CA). When the private key is configured along with a matching certificate, the "signature_algorithms_cert" extension is handled reliably even without the fix, and peer clients or servers that don't support raw public keys may be able to complete a TLS connection by pinning or verifying the corresponding certificate or its public key. Deployments that prefer to configure just a private key with no certificate need to upgrade to an updated release as noted below. FIPS impact: no No FIPS modules are affected by this issue, as the SSL protocol implementation is outside the OpenSSL FIPS module boundary.
      Weakness type (CWE)added
      —
      CWE-476
      Referenceadded
      —
      https://github.com/openssl/openssl/commit/1e8c398db67404babd3e5af999bb6bd86f720c76
      Referenceadded
      —
      https://github.com/openssl/openssl/commit/581aaa0f0a35d214740f0fe1f5283ec41f1212e1
      Referenceadded
      —
      https://github.com/openssl/openssl/commit/d0af20478688a6aa2f59d61caa3f82136b181d7f
      Referenceadded
      —
      https://github.com/openssl/openssl/commit/dad836b071da6579510c968615848ba03cac593b
      Referenceadded
      —
      https://openssl-library.org/news/secadv/20260825.txt

      Source identifier: openssl-security@openssl.org

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