Vulnerability-Lookup

FKIE_CVE-2026-74670

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-25 06:18

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: ipvs: stop estimator after disabled calc phase IPVS estimator kthread 0 starts with zeroed chain and tick limits until its initial calculation phase completes. If network namespace teardown clears ipvs->enable during that phase, ip_vs_est_calc_phase() can return without installing positive limits. The kthread can then continue into its main loop and drain est_temp_list with zero chain_max, tick_max and est_max_count values. Each enqueue consumes one available tick row, but est_count never reaches the zero est_max_count value. After all rows are consumed, the row lookup returns IPVS_EST_NTICKS and ip_vs_enqueue_estimator() writes past the ticks and tick_len arrays. Exit kthread 0 after the calculation phase if the kthread is stopping or IPVS has been disabled. That keeps temporary estimators from being drained after the limits failed to initialize. Estimator kthreads can now self-exit before teardown or reload stops kd->task. Keep an extra task reference after creation and release it with kthread_stop_put(), so kd->task remains valid until the stop paths consume that reference.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2335dedc1922dfa889ca1f9f70370924e8e79a08
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/558f67f1340f803a346ecd14a69c49653111c5f4
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d5122a2b2601145975d387006e517c56896e310e
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/de98dc5ef94b83bbb444c670c253ea02ca0f5e43
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e7f34f29b330265d456943bf0b984dcecfcef9af

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/ipvs/ip_vs_est.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d5122a2b2601145975d387006e517c56896e310e",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "de98dc5ef94b83bbb444c670c253ea02ca0f5e43",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "e7f34f29b330265d456943bf0b984dcecfcef9af",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "2335dedc1922dfa889ca1f9f70370924e8e79a08",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "558f67f1340f803a346ecd14a69c49653111c5f4",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/ipvs/ip_vs_est.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: stop estimator after disabled calc phase\n\nIPVS estimator kthread 0 starts with zeroed chain and tick limits until\nits initial calculation phase completes. If network namespace teardown\nclears ipvs-\u003eenable during that phase, ip_vs_est_calc_phase() can return\nwithout installing positive limits.\n\nThe kthread can then continue into its main loop and drain\nest_temp_list with zero chain_max, tick_max and est_max_count values.\nEach enqueue consumes one available tick row, but est_count never\nreaches the zero est_max_count value. After all rows are consumed, the\nrow lookup returns IPVS_EST_NTICKS and ip_vs_enqueue_estimator() writes\npast the ticks and tick_len arrays.\n\nExit kthread 0 after the calculation phase if the kthread is stopping or\nIPVS has been disabled. That keeps temporary estimators from being\ndrained after the limits failed to initialize.\n\nEstimator kthreads can now self-exit before teardown or reload stops\nkd-\u003etask. Keep an extra task reference after creation and release it\nwith kthread_stop_put(), so kd-\u003etask remains valid until the stop paths\nconsume that reference."
    }
  ],
  "id": "CVE-2026-74670",
  "lastModified": "2026-08-25T06:18:49.380",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:40.953",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2335dedc1922dfa889ca1f9f70370924e8e79a08"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/558f67f1340f803a346ecd14a69c49653111c5f4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5122a2b2601145975d387006e517c56896e310e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/de98dc5ef94b83bbb444c670c253ea02ca0f5e43"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e7f34f29b330265d456943bf0b984dcecfcef9af"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-74670 (GCVE-0-2026-74670)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:32 – Updated: 2026-08-25 05:41

Title

ipvs: stop estimator after disabled calc phase

Summary

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 mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/d5122a2b260114597…
https://git.kernel.org/stable/c/de98dc5ef94b83bbb…
https://git.kernel.org/stable/c/e7f34f29b330265d4…
https://git.kernel.org/stable/c/2335dedc1922dfa88…
https://git.kernel.org/stable/c/558f67f1340f803a3…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 705dd34440812735ece298eb5bc153fde9544d42 , < d5122a2b2601145975d387006e517c56896e310e (git) Affected: 705dd34440812735ece298eb5bc153fde9544d42 , < de98dc5ef94b83bbb444c670c253ea02ca0f5e43 (git) Affected: 705dd34440812735ece298eb5bc153fde9544d42 , < e7f34f29b330265d456943bf0b984dcecfcef9af (git) Affected: 705dd34440812735ece298eb5bc153fde9544d42 , < 2335dedc1922dfa889ca1f9f70370924e8e79a08 (git) Affected: 705dd34440812735ece298eb5bc153fde9544d42 , < 558f67f1340f803a346ecd14a69c49653111c5f4 (git)
Linux	Linux	Affected: 6.2 Unaffected: 0 , < 6.2 (semver) Unaffected: 6.6.152 , ≤ 6.6.* (semver) Unaffected: 6.12.104 , ≤ 6.12.* (semver) Unaffected: 6.18.45 , ≤ 6.18.* (semver) Unaffected: 7.1.9 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/ipvs/ip_vs_est.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d5122a2b2601145975d387006e517c56896e310e",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "de98dc5ef94b83bbb444c670c253ea02ca0f5e43",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "e7f34f29b330265d456943bf0b984dcecfcef9af",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "2335dedc1922dfa889ca1f9f70370924e8e79a08",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            },
            {
              "lessThan": "558f67f1340f803a346ecd14a69c49653111c5f4",
              "status": "affected",
              "version": "705dd34440812735ece298eb5bc153fde9544d42",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/ipvs/ip_vs_est.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.152",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.104",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.45",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.9",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: stop estimator after disabled calc phase\n\nIPVS estimator kthread 0 starts with zeroed chain and tick limits until\nits initial calculation phase completes. If network namespace teardown\nclears ipvs-\u003eenable during that phase, ip_vs_est_calc_phase() can return\nwithout installing positive limits.\n\nThe kthread can then continue into its main loop and drain\nest_temp_list with zero chain_max, tick_max and est_max_count values.\nEach enqueue consumes one available tick row, but est_count never\nreaches the zero est_max_count value. After all rows are consumed, the\nrow lookup returns IPVS_EST_NTICKS and ip_vs_enqueue_estimator() writes\npast the ticks and tick_len arrays.\n\nExit kthread 0 after the calculation phase if the kthread is stopping or\nIPVS has been disabled. That keeps temporary estimators from being\ndrained after the limits failed to initialize.\n\nEstimator kthreads can now self-exit before teardown or reload stops\nkd-\u003etask. Keep an extra task reference after creation and release it\nwith kthread_stop_put(), so kd-\u003etask remains valid until the stop paths\nconsume that reference."
        }
      ],
      "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"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Exploitation requires local IPVS configuration via netlink or setsockopt (GENL_ADMIN_PERM/CAP_NET_ADMIN); the bug is in estimator kthread management during namespace teardown, not in remote packet handling.\nAC:L - The attacker controls both sides of the race by creating a network namespace, adding many IPVS services to populate est_temp_list, and tearing down the namespace during kthread 0\u0027s calc phase.\nPR:L - Triggering IPVS service creation and namespace teardown requires CAP_NET_ADMIN, which unprivileged users can obtain in user+network namespaces via unshare on systems with unprivileged user namespaces enabled.\nUI:N - No victim interaction is required; an attacker can script IPVS service creation and namespace destruction without any action from another user or administrator.\nS:U - The out-of-bounds write corrupts kernel heap memory within the same kernel security boundary; impact is local privilege escalation or denial of service, not a cross-boundary escape.\nC:H - Out-of-bounds writes past ticks[] and tick_len[] corrupt adjacent heap metadata and kernel structures, providing a memory corruption primitive that can be leveraged for arbitrary kernel memory disclosure.\nI:H - Writing past the fixed-size ticks[] and tick_len[] arrays enables heap corruption that can overwrite function pointers or adjacent objects, supporting arbitrary kernel write and potential code execution.\nA:H - Heap corruption from unbounded index writes in ip_vs_enqueue_estimator() can cause kernel oops, panic, or hang when processing estimators after failed calc-phase initialization."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T05:41:25.343Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d5122a2b2601145975d387006e517c56896e310e"
        },
        {
          "url": "https://git.kernel.org/stable/c/de98dc5ef94b83bbb444c670c253ea02ca0f5e43"
        },
        {
          "url": "https://git.kernel.org/stable/c/e7f34f29b330265d456943bf0b984dcecfcef9af"
        },
        {
          "url": "https://git.kernel.org/stable/c/2335dedc1922dfa889ca1f9f70370924e8e79a08"
        },
        {
          "url": "https://git.kernel.org/stable/c/558f67f1340f803a346ecd14a69c49653111c5f4"
        }
      ],
      "title": "ipvs: stop estimator after disabled calc phase",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74670",
    "datePublished": "2026-08-22T15:32:40.850Z",
    "dateReserved": "2026-08-15T05:44:03.925Z",
    "dateUpdated": "2026-08-25T05:41:25.343Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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FKIE_CVE-2026-74670

CVE-2026-74670 (GCVE-0-2026-74670)

Tags

Sightings

Nomenclature