Vulnerability-Lookup

CVE-2026-43491 (GCVE-0-2026-43491)

Vulnerability from cvelistv5 – Published: 2026-05-19 10:44 – Updated: 2026-05-19 10:44

Title

net: qrtr: ns: Limit the maximum server registration per node

Summary

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: ns: Limit the maximum server registration per node Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory. Fix this issue by limiting the maximum number of server registrations to 256 per node. If the NEW_SERVER message is received for an old port, then don't restrict it as it will get replaced. While at it, also rate limit the error messages in the failure path of qrtr_ns_worker(). Note that the limit of 256 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

Severity ?

No CVSS data available.

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/e6f6cd501fb540609…
https://git.kernel.org/stable/c/3efaad55cad1ded42…
https://git.kernel.org/stable/c/35fb4a0c077c5d104…
https://git.kernel.org/stable/c/868202aa2adae4270…
https://git.kernel.org/stable/c/d5ee2ff9832233795…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 0c2204a4ad710d95d348ea006f14ba926e842ffd , < e6f6cd501fb54060940a6eb3f4103eeb5e426ae7 (git) Affected: 0c2204a4ad710d95d348ea006f14ba926e842ffd , < 3efaad55cad1ded429e3a873bfece389058a526b (git) Affected: 0c2204a4ad710d95d348ea006f14ba926e842ffd , < 35fb4a0c077c5d1049c2628b769e0a1b1e65df0d (git) Affected: 0c2204a4ad710d95d348ea006f14ba926e842ffd , < 868202aa2adae427060a42d5bd663b4d782ec02c (git) Affected: 0c2204a4ad710d95d348ea006f14ba926e842ffd , < d5ee2ff98322337951c56398e79d51815acbf955 (git)
Linux	Linux	Affected: 5.7 Unaffected: 0 , < 5.7 (semver) Unaffected: 6.6.140 , ≤ 6.6.* (semver) Unaffected: 6.12.86 , ≤ 6.12.* (semver) Unaffected: 6.18.27 , ≤ 6.18.* (semver) Unaffected: 7.0.4 , ≤ 7.0.* (semver) Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
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          "programFiles": [
            "net/qrtr/ns.c"
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    "datePublished": "2026-05-19T10:44:23.832Z",
    "dateReserved": "2026-05-01T14:12:56.013Z",
    "dateUpdated": "2026-05-19T10:44:23.832Z",
    "state": "PUBLISHED"
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}

FKIE_CVE-2026-43491

Vulnerability from fkie_nvd - Published: 2026-05-19 12:16 - Updated: 2026-05-19 12:16

Severity ?

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/35fb4a0c077c5d1049c2628b769e0a1b1e65df0d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3efaad55cad1ded429e3a873bfece389058a526b
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/868202aa2adae427060a42d5bd663b4d782ec02c
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d5ee2ff98322337951c56398e79d51815acbf955
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e6f6cd501fb54060940a6eb3f4103eeb5e426ae7

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: qrtr: ns: Limit the maximum server registration per node\n\nCurrent code does no bound checking on the number of servers added per\nnode. A malicious client can flood NEW_SERVER messages and exhaust memory.\n\nFix this issue by limiting the maximum number of server registrations to\n256 per node. If the NEW_SERVER message is received for an old port, then\ndon\u0027t restrict it as it will get replaced. While at it, also rate limit\nthe error messages in the failure path of qrtr_ns_worker().\n\nNote that the limit of 256 is chosen based on the current platform\nrequirements. If requirement changes in the future, this limit can be\nincreased."
    }
  ],
  "id": "CVE-2026-43491",
  "lastModified": "2026-05-19T12:16:18.747",
  "metrics": {},
  "published": "2026-05-19T12:16:18.747",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/35fb4a0c077c5d1049c2628b769e0a1b1e65df0d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3efaad55cad1ded429e3a873bfece389058a526b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/868202aa2adae427060a42d5bd663b4d782ec02c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5ee2ff98322337951c56398e79d51815acbf955"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e6f6cd501fb54060940a6eb3f4103eeb5e426ae7"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-VFQF-4C37-R857

Vulnerability from github – Published: 2026-05-19 12:31 – Updated: 2026-05-19 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

net: qrtr: ns: Limit the maximum server registration per node

Current code does no bound checking on the number of servers added per node. A malicious client can flood NEW_SERVER messages and exhaust memory.

Fix this issue by limiting the maximum number of server registrations to 256 per node. If the NEW_SERVER message is received for an old port, then don't restrict it as it will get replaced. While at it, also rate limit the error messages in the failure path of qrtr_ns_worker().

Note that the limit of 256 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-43491"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-19T12:16:18Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: qrtr: ns: Limit the maximum server registration per node\n\nCurrent code does no bound checking on the number of servers added per\nnode. A malicious client can flood NEW_SERVER messages and exhaust memory.\n\nFix this issue by limiting the maximum number of server registrations to\n256 per node. If the NEW_SERVER message is received for an old port, then\ndon\u0027t restrict it as it will get replaced. While at it, also rate limit\nthe error messages in the failure path of qrtr_ns_worker().\n\nNote that the limit of 256 is chosen based on the current platform\nrequirements. If requirement changes in the future, this limit can be\nincreased.",
  "id": "GHSA-vfqf-4c37-r857",
  "modified": "2026-05-19T12:31:41Z",
  "published": "2026-05-19T12:31:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43491"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/35fb4a0c077c5d1049c2628b769e0a1b1e65df0d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3efaad55cad1ded429e3a873bfece389058a526b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/868202aa2adae427060a42d5bd663b4d782ec02c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d5ee2ff98322337951c56398e79d51815acbf955"
    },
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      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e6f6cd501fb54060940a6eb3f4103eeb5e426ae7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

MSRC_CVE-2026-43491

Vulnerability from csaf_microsoft - Published: 2026-05-02 00:00 - Updated: 2026-05-20 01:01

Summary

net: qrtr: ns: Limit the maximum server registration per node

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-2026-43491

Affected products

Under investigation 1 product

Product	Identifier	Version	Remediation
Unresolved product id: 17084-1		—

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-2026-43491 net: qrtr: ns: Limit the maximum server registration per node - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-43491.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": "net: qrtr: ns: Limit the maximum server registration per node",
    "tracking": {
      "current_release_date": "2026-05-20T01:01:33.000Z",
      "generator": {
        "date": "2026-05-20T07:12:03.239Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-43491",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-20T01:01:33.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
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  "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"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-43491",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "under_investigation": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-43491 net: qrtr: ns: Limit the maximum server registration per node - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-43491.json"
        }
      ],
      "title": "net: qrtr: ns: Limit the maximum server registration per node"
    }
  ]
}

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-2026-43491 (GCVE-0-2026-43491)

FKIE_CVE-2026-43491

GHSA-VFQF-4C37-R857

MSRC_CVE-2026-43491

Tags

Sightings

Nomenclature