Vulnerability-Lookup

CVE-2026-58250 (GCVE-0-2026-58250)

Vulnerability from cvelistv5 – Published: 2026-07-08 19:48 – Updated: 2026-07-09 13:33

Title

NATS Server: Pre-auth server crash via double INFO in leafnode handshake

Summary

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.12.8 and 2.11.17, an unauthenticated peer with network access to a leafnode listener with compression enabled could crash the server during the pre-authentication leafnode handshake by sending repeated leafnode INFO protocol messages before authentication and account setup completed. This issue is fixed in versions 2.12.8 and 2.11.17.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-476 - NULL Pointer Dereference

Assigner

GitHub_M

References

5 references

URL	Tags
https://github.com/nats-io/nats-server/security/a…	x_refsource_CONFIRM
https://github.com/nats-io/nats-server/commit/8dc…	x_refsource_MISC
https://github.com/nats-io/nats-server/commit/fc5…	x_refsource_MISC
https://github.com/nats-io/nats-server/releases/t…	x_refsource_MISC
https://github.com/nats-io/nats-server/releases/t…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
nats-io	nats-server	Affected: < 2.11.17 Affected: >= 2.12.0-preview.1, < 2.12.8

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-58250

Vulnerability from fkie_nvd - Published: 2026-07-08 20:16 - Updated: 2026-07-13 15:18

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

URL	Tags
security-advisories@github.com	https://github.com/nats-io/nats-server/commit/8dcb26eaea78fdcbe96dbee5986d6019fd5cb94a	Patch
security-advisories@github.com	https://github.com/nats-io/nats-server/commit/fc5fe39177533e9dbdd651d2458285bfae1dde27	Patch
security-advisories@github.com	https://github.com/nats-io/nats-server/releases/tag/v2.11.17	Release Notes
security-advisories@github.com	https://github.com/nats-io/nats-server/releases/tag/v2.12.8	Release Notes
security-advisories@github.com	https://github.com/nats-io/nats-server/security/advisories/GHSA-3g5q-cfh2-cq67	Vendor Advisory

Impacted products

	Vendor	Product	Version
	linuxfoundation	nats-server	*
	linuxfoundation	nats-server	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "nats-server",
          "vendor": "nats-io",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.11.17"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.12.0-preview.1, \u003c 2.12.8"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
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    }
  ],
  "id": "CVE-2026-58250",
  "lastModified": "2026-07-13T15:18:46.507",
  "metrics": {
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          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
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}

MSRC_CVE-2026-58250

Vulnerability from csaf_microsoft - Published: 2026-07-02 00:00 - Updated: 2026-07-11 01:08

Summary

NATS Server: Pre-auth server crash via double INFO in leafnode handshake

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-2026-58250

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE-476 - NULL Pointer Dereference

Affected products

Known affected 1 product

Product	Identifier	Version	Remediation
Unresolved product id: 17084-1		—	None Available

References

4 references

URL	Category
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self
https://support.microsoft.com/lifecycle	external
https://www.first.org/cvss	external
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self

JSON

To clipboard

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "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-2026-58250 NATS Server: Pre-auth server crash via double INFO in leafnode handshake - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-58250.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": "NATS Server: Pre-auth server crash via double INFO in leafnode handshake",
    "tracking": {
      "current_release_date": "2026-07-11T01:08:08.000Z",
      "generator": {
        "date": "2026-07-11T07:31:31.451Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-58250",
      "initial_release_date": "2026-07-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-07-11T01:08:08.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "azl3 telegraf 0:1.31.0-23.azl3",
                "product": {
                  "name": "azl3 telegraf 0:1.31.0-23.azl3",
                  "product_id": "1"
                }
              }
            ],
            "category": "product_name",
            "name": "telegraf"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 telegraf 0:1.31.0-23.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-58250",
      "cwe": {
        "id": "CWE-476",
        "name": "NULL Pointer Dereference"
      },
      "notes": [
        {
          "category": "general",
          "text": "GitHub_M",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-58250 NATS Server: Pre-auth server crash via double INFO in leafnode handshake - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-58250.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-07-11T01:08:08.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "temporalScore": 7.5,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "17084-1"
          ]
        }
      ],
      "title": "NATS Server: Pre-auth server crash via double INFO in leafnode handshake"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-58250 (GCVE-0-2026-58250)

FKIE_CVE-2026-58250

MSRC_CVE-2026-58250

Tags

Sightings

Nomenclature