HighCVE-2026-95208

    Improper Certificate Validation (CVE-2026-95208)

    Published Last modified Sources: CVE.org, EUVD

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    What is affected, what to do

    An issue in the ConfirmNameConstraints() function (wolfcrypt/src/asn.c) of wolfSSL v5.9.1 and v5.9.2 allows attackers to cause a Denial of Service (DoS) via providing crafted Certificate Authority certificates, leading to valid certificates without SAN to be incorrectly rejected by wolfSSL-based TLS clients. NOTE: this is disputed by multiple parties because the behavior does not offer a new ability for an adversary to conduct a denial of service, and because the product can reasonably choose to enforce a dNSName constraint against Common Name when Subject Alternative Name is absent.

    The available sources name no fixed version. Check the vendor guidance in the references below.

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

    Metrics

    7.5

    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: CVE.org, EUVD

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 6.7

    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
    66.84 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
    0.2 %
    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
    6.7
    Low — this CVE sits in the lower 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 · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 8 October 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-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
    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

    An issue in the ConfirmNameConstraints() function (wolfcrypt/src/asn.c) of wolfSSL v5.9.1 and v5.9.2 allows attackers to cause a Denial of Service (DoS) via providing crafted Certificate Authority certificates, leading to valid certificates without SAN to be incorrectly rejected by wolfSSL-based TLS clients. NOTE: this is disputed by multiple parties because the behavior does not offer a new ability for an adversary to conduct a denial of service, and because the product can reasonably choose to enforce a dNSName constraint against Common Name when Subject Alternative Name is absent.

    Source: NVD (NIST), ENISA EUVD, cvelistv5

    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

    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. RejectedMITRE

    2. Record modifiedMITRE

      No longer listed as affected:

      CVSS V3.1: before CISA-ADP: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, after —

      CVSS V3.1: before nvd-ai-agent-0.4.0-gemma-4-31B-it: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, after —

      Description added or changed

      Show 15 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentremoved
      {"id":"CVE-2026-95208","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-08T20:15:53.665475Z"}
      —
      Tagremoved
      MITRE: disputed
      —
      Descriptionchanged
      An issue in the ConfirmNameConstraints() function (wolfcrypt/src/asn.c) of wolfSSL v5.9.1 and v5.9.2 allows attackers to cause a Denial of Service (DoS) via providing crafted Certificate Authority certificates, leading to valid certificates without SAN to be incorrectly rejected by wolfSSL-based TLS clients. NOTE: this is disputed by multiple parties because the behavior does not offer a new ability for an adversary to conduct a denial of service, and because the product can reasonably choose to enforce a dNSName constraint against Common Name when Subject Alternative Name is absent.
      Rejected reason: ** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: none. Reason: This candidate was withdrawn by its CNA. Further investigation showed that it was not a security issue. Notes: none.
      CVSSremoved
      CISA-ADP: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
      —
      CVSSremoved
      nvd-ai-agent-0.4.0-gemma-4-31B-it: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
      —
      Weakness type (CWE)removed
      CISA-ADP: CWE-295
      —
      Weakness type (CWE)removed
      nvd-ai-agent-0.4.0-gemma-4-31B-it: CWE-295
      —
      Product configurationremoved
      OR *cpe:2.3:a:wolfssl:wolfssl:5.9.2:*:*:*:*:*:*:* *cpe:2.3:a:wolfssl:wolfssl:5.9.1:*:*:*:*:*:*:*
      —
      Affected versions (publisher)added
      —
      Affected value removed. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/95xxx/CVE-2026-95208.json">CVE-2026-95208</a>
      Referenceremoved
      MITRE: http://wolfssl.com
      —
      Referenceremoved
      MITRE: https://gist.github.com/lkloliver/14edf8bbfbf5769949b85c7f5cc2eba2
      —
      Referenceremoved
      nvd-ai-agent-0.4.0-gemma-4-31B-it: http://wolfssl.com
      —
      Referenceremoved
      nvd-ai-agent-0.4.0-gemma-4-31B-it: https://gist.github.com/lkloliver/14edf8bbfbf5769949b85c7f5cc2eba2
      —
      Reference typeremoved
      nvd-ai-agent-0.4.0-gemma-4-31B-it: http://wolfssl.com Types: Product
      —
      Reference typeremoved
      nvd-ai-agent-0.4.0-gemma-4-31B-it: https://gist.github.com/lkloliver/14edf8bbfbf5769949b85c7f5cc2eba2 Types: Exploit, Third Party Advisory
      —

      Source identifier: cve@mitre.org

    3. Record modifiedMITRE

      Description added or changed

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Tagadded
      —
      disputed
      Descriptionchanged
      An issue in the ConfirmNameConstraints() function (wolfcrypt/src/asn.c) of wolfSSL v5.9.1 and v5.9.2 allows attackers to cause a Denial of Service (DoS) via providing crafted Certificate Authority certificates, leading to valid certificates without SAN to be incorrectly rejected by wolfSSL-based TLS clients.
      An issue in the ConfirmNameConstraints() function (wolfcrypt/src/asn.c) of wolfSSL v5.9.1 and v5.9.2 allows attackers to cause a Denial of Service (DoS) via providing crafted Certificate Authority certificates, leading to valid certificates without SAN to be incorrectly rejected by wolfSSL-based TLS clients. NOTE: this is disputed by multiple parties because the behavior does not offer a new ability for an adversary to conduct a denial of service, and because the product can reasonably choose to enforce a dNSName constraint against Common Name when Subject Alternative Name is absent.

      Source identifier: cve@mitre.org

    4. Record modifiedCISA ADP

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

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Weakness type: CWE-295

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
      Weakness type (CWE)added
      —
      CWE-295
      SSVC assessmentadded
      —
      {"id":"CVE-2026-95208","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-08T20:15:53.665475Z"}

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

    5. ReceivedMITRE

      Description added or changed

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      An issue in the ConfirmNameConstraints() function (wolfcrypt/src/asn.c) of wolfSSL v5.9.1 and v5.9.2 allows attackers to cause a Denial of Service (DoS) via providing crafted Certificate Authority certificates, leading to valid certificates without SAN to be incorrectly rejected by wolfSSL-based TLS clients.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/95xxx/CVE-2026-95208.json">CVE-2026-95208</a>
      Referenceadded
      —
      http://wolfssl.com
      Referenceadded
      —
      https://gist.github.com/lkloliver/14edf8bbfbf5769949b85c7f5cc2eba2

      Source identifier: cve@mitre.org

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