Vulnerability-Lookup

GHSA-9WJ8-78X3-52F8

Vulnerability from github – Published: 2026-04-03 18:31 – Updated: 2026-04-23 21:31

Details

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

net: shaper: protect late read accesses to the hierarchy

We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections.

This is not proper, a conversion from a ref to a locked netdev must include a liveness check (a check if the netdev hasn't been unregistered already). Fix the read cases (those under RCU). Writes needs a separate change to protect from creating the hierarchy after flush has already run.

Severity ?

5.5 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23437"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-03T16:16:25Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: shaper: protect late read accesses to the hierarchy\n\nWe look up a netdev during prep of Netlink ops (pre- callbacks)\nand take a ref to it. Then later in the body of the callback\nwe take its lock or RCU which are the actual protections.\n\nThis is not proper, a conversion from a ref to a locked netdev\nmust include a liveness check (a check if the netdev hasn\u0027t been\nunregistered already). Fix the read cases (those under RCU).\nWrites needs a separate change to protect from creating the\nhierarchy after flush has already run.",
  "id": "GHSA-9wj8-78x3-52f8",
  "modified": "2026-04-23T21:31:18Z",
  "published": "2026-04-03T18:31:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23437"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f9ea7141f365b4f27226898e62220fb98ef8dc6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/348758ba74e6a348299965b16a97cfb817545cc0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/581eee0890a8bde44f1fb78ad3e70502a897d583"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-23437 (GCVE-0-2026-23437)

Vulnerability from cvelistv5 – Published: 2026-04-03 15:15 – Updated: 2026-04-27 14:02

Title

net: shaper: protect late read accesses to the hierarchy

Summary

In the Linux kernel, the following vulnerability has been resolved: net: shaper: protect late read accesses to the hierarchy We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections. This is not proper, a conversion from a ref to a locked netdev must include a liveness check (a check if the netdev hasn't been unregistered already). Fix the read cases (those under RCU). Writes needs a separate change to protect from creating the hierarchy after flush has already run.

Severity ?

7.8 (High)


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

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/581eee0890a8bde44…
	https://git.kernel.org/stable/c/348758ba74e6a3482…
	https://git.kernel.org/stable/c/0f9ea7141f365b4f2…

Impacted products

Vendor

Product

Version

Linux

Affected: 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb , < 581eee0890a8bde44f1fb78ad3e70502a897d583 (git)
Affected: 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb , < 348758ba74e6a348299965b16a97cfb817545cc0 (git)
Affected: 4b623f9f0f59652ea71fcb27d60b4c3b65126dbb , < 0f9ea7141f365b4f27226898e62220fb98ef8dc6 (git)

Linux

Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 6.18.20 , ≤ 6.18.* (semver)
Unaffected: 6.19.10 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/shaper/shaper.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "581eee0890a8bde44f1fb78ad3e70502a897d583",
              "status": "affected",
              "version": "4b623f9f0f59652ea71fcb27d60b4c3b65126dbb",
              "versionType": "git"
            },
            {
              "lessThan": "348758ba74e6a348299965b16a97cfb817545cc0",
              "status": "affected",
              "version": "4b623f9f0f59652ea71fcb27d60b4c3b65126dbb",
              "versionType": "git"
            },
            {
              "lessThan": "0f9ea7141f365b4f27226898e62220fb98ef8dc6",
              "status": "affected",
              "version": "4b623f9f0f59652ea71fcb27d60b4c3b65126dbb",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/shaper/shaper.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.20",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.10",
              "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": "6.18.20",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.10",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: shaper: protect late read accesses to the hierarchy\n\nWe look up a netdev during prep of Netlink ops (pre- callbacks)\nand take a ref to it. Then later in the body of the callback\nwe take its lock or RCU which are the actual protections.\n\nThis is not proper, a conversion from a ref to a locked netdev\nmust include a liveness check (a check if the netdev hasn\u0027t been\nunregistered already). Fix the read cases (those under RCU).\nWrites needs a separate change to protect from creating the\nhierarchy after flush has already run."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-27T14:02:24.149Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/581eee0890a8bde44f1fb78ad3e70502a897d583"
        },
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          "url": "https://git.kernel.org/stable/c/348758ba74e6a348299965b16a97cfb817545cc0"
        },
        {
          "url": "https://git.kernel.org/stable/c/0f9ea7141f365b4f27226898e62220fb98ef8dc6"
        }
      ],
      "title": "net: shaper: protect late read accesses to the hierarchy",
      "x_generator": {
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      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23437",
    "datePublished": "2026-04-03T15:15:22.048Z",
    "dateReserved": "2026-01-13T15:37:46.017Z",
    "dateUpdated": "2026-04-27T14:02:24.149Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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

GHSA-9WJ8-78X3-52F8

CVE-2026-23437 (GCVE-0-2026-23437)

Tags

Sightings

Nomenclature