MSRC_CVE-2026-23439

Vulnerability from csaf_microsoft - Published: 2026-04-02 00:00 - Updated: 2026-04-25 01:05
Summary
udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
Notes
Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
CVE-2026-23439
None Available There is no fix available for this vulnerability as of now
References
To clipboard 

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
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    "notes": [
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        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-23439 udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-23439.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n",
    "tracking": {
      "current_release_date": "2026-04-25T01:05:20.000Z",
      "generator": {
        "date": "2026-04-25T07:24:18.201Z",
        "engine": {
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      },
      "id": "msrc_CVE-2026-23439",
      "initial_release_date": "2026-04-02T00:00:00.000Z",
      "revision_history": [
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          "date": "2026-04-25T01:05:20.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
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      "status": "final",
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  "product_tree": {
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      {
        "branches": [
          {
            "branches": [
              {
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                  "product_id": "17086"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "cbl2 kernel 0:5.15.202.1-1.cbl2",
                "product": {
                  "name": "cbl2 kernel 0:5.15.202.1-1.cbl2",
                  "product_id": "1"
                }
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            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
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    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "cbl2 kernel 0:5.15.202.1-1.cbl2 as a component of CBL Mariner 2.0",
          "product_id": "17086-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17086"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-23439",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17086-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-23439 udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-23439.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-04-25T01:05:20.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17086-1"
          ]
        }
      ],
      "title": "udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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