Vulnerability-Lookup

CVE-2026-43042 (GCVE-0-2026-43042)

Vulnerability from cvelistv5 – Published: 2026-05-01 14:15 – Updated: 2026-05-03 05:46

Title

mpls: add seqcount to protect the platform_label{,s} pair

Summary

In the Linux kernel, the following vulnerability has been resolved: mpls: add seqcount to protect the platform_label{,s} pair The RCU-protected codepaths (mpls_forward, mpls_dump_routes) can have an inconsistent view of platform_labels vs platform_label in case of a concurrent resize (resize_platform_label_table, under platform_mutex). This can lead to OOB accesses. This patch adds a seqcount, so that we get a consistent snapshot. Note that mpls_label_ok is also susceptible to this, so the check against RTA_DST in rtm_to_route_config, done outside platform_mutex, is not sufficient. This value gets passed to mpls_label_ok once more in both mpls_route_add and mpls_route_del, so there is no issue, but that additional check must not be removed.

Severity ?

7.1 (High)


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

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/5bb3caf0bbfb56f1a…
	https://git.kernel.org/stable/c/629ec78ef8608d955…

Impacted products

Vendor

Product

Version

Linux

Affected: 7720c01f3f590116882e251f13c7e1d5602f8643 , < 5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef (git)
Affected: 7720c01f3f590116882e251f13c7e1d5602f8643 , < 629ec78ef8608d955ce217880cdc3e1873af3a15 (git)

Linux

Affected: 4.1
Unaffected: 0 , < 4.1 (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/netns/mpls.h",
            "net/mpls/af_mpls.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef",
              "status": "affected",
              "version": "7720c01f3f590116882e251f13c7e1d5602f8643",
              "versionType": "git"
            },
            {
              "lessThan": "629ec78ef8608d955ce217880cdc3e1873af3a15",
              "status": "affected",
              "version": "7720c01f3f590116882e251f13c7e1d5602f8643",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/netns/mpls.h",
            "net/mpls/af_mpls.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.1"
            },
            {
              "lessThan": "4.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.12",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "7.0",
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                  "vulnerable": true
                }
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              "negate": false,
              "operator": "OR"
            }
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmpls: add seqcount to protect the platform_label{,s} pair\n\nThe RCU-protected codepaths (mpls_forward, mpls_dump_routes) can have\nan inconsistent view of platform_labels vs platform_label in case of a\nconcurrent resize (resize_platform_label_table, under\nplatform_mutex). This can lead to OOB accesses.\n\nThis patch adds a seqcount, so that we get a consistent snapshot.\n\nNote that mpls_label_ok is also susceptible to this, so the check\nagainst RTA_DST in rtm_to_route_config, done outside platform_mutex,\nis not sufficient. This value gets passed to mpls_label_ok once more\nin both mpls_route_add and mpls_route_del, so there is no issue, but\nthat additional check must not be removed."
        }
      ],
      "metrics": [
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            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          }
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-03T05:46:19.755Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef"
        },
        {
          "url": "https://git.kernel.org/stable/c/629ec78ef8608d955ce217880cdc3e1873af3a15"
        }
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43042",
    "datePublished": "2026-05-01T14:15:38.882Z",
    "dateReserved": "2026-05-01T14:12:55.978Z",
    "dateUpdated": "2026-05-03T05:46:19.755Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
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    "epss": {
      "cve": "CVE-2026-43042",
      "date": "2026-05-04",
      "epss": "0.00013",
      "percentile": "0.02103"
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  }
}

MSRC_CVE-2026-43042

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

Summary

mpls: add seqcount to protect the platform_label{,s} pair

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-2026-43042

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-2026-43042 mpls: add seqcount to protect the platform_label{,s} pair - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-43042.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": "mpls: add seqcount to protect the platform_label{,s} pair",
    "tracking": {
      "current_release_date": "2026-05-02T01:02:47.000Z",
      "generator": {
        "date": "2026-05-03T07:02:17.470Z",
        "engine": {
          "name": "MSRC Generator",
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        }
      },
      "id": "msrc_CVE-2026-43042",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
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          "date": "2026-05-02T01:02:47.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
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  "product_tree": {
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                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
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            "category": "product_name",
            "name": "Azure Linux"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
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  "vulnerabilities": [
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      "notes": [
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          "text": "Linux",
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        }
      ],
      "title": "mpls: add seqcount to protect the platform_label{,s} pair"
    }
  ]
}

FKIE_CVE-2026-43042

Vulnerability from fkie_nvd - Published: 2026-05-01 15:16 - Updated: 2026-05-03 07:16

Severity ?

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

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/629ec78ef8608d955ce217880cdc3e1873af3a15

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmpls: add seqcount to protect the platform_label{,s} pair\n\nThe RCU-protected codepaths (mpls_forward, mpls_dump_routes) can have\nan inconsistent view of platform_labels vs platform_label in case of a\nconcurrent resize (resize_platform_label_table, under\nplatform_mutex). This can lead to OOB accesses.\n\nThis patch adds a seqcount, so that we get a consistent snapshot.\n\nNote that mpls_label_ok is also susceptible to this, so the check\nagainst RTA_DST in rtm_to_route_config, done outside platform_mutex,\nis not sufficient. This value gets passed to mpls_label_ok once more\nin both mpls_route_add and mpls_route_del, so there is no issue, but\nthat additional check must not be removed."
    }
  ],
  "id": "CVE-2026-43042",
  "lastModified": "2026-05-03T07:16:23.670",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-01T15:16:50.423",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5bb3caf0bbfb56f1a00d2af072ac3d8395a3b9ef"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/629ec78ef8608d955ce217880cdc3e1873af3a15"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

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-2026-43042 (GCVE-0-2026-43042)

MSRC_CVE-2026-43042

FKIE_CVE-2026-43042

Tags

Sightings

Nomenclature