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GHSA-FWJP-32V8-7PP8

Vulnerability from github – Published: 2026-10-06 09:31 – Updated: 2026-10-07 09:32

Details

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

futex: Also allocate private hash on vfork()

As Jann demonstrated, it is entirely feasible to access the mm through vfork(). Therefore we need to allocate a private hash on vfork() as well as any other CLONE_VM user.

Specifically, it must be avoided to have (private) futex waiters before allocating the private hash.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-98281"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-06T09:18:18Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Also allocate private hash on vfork()\n\nAs Jann demonstrated, it is entirely feasible to access the mm through vfork().\nTherefore we need to allocate a private hash on vfork() as well as any other\nCLONE_VM user.\n\nSpecifically, it must be avoided to have (private) futex waiters before\nallocating the private hash.",
  "id": "GHSA-fwjp-32v8-7pp8",
  "modified": "2026-10-07T09:32:15Z",
  "published": "2026-10-06T09:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98281"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5468a4855b63b30156a79e5248e01bf1a2c18dd7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b61b6f95d6722ddbbbd09e689fa41b55fd36f9a5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eecbafa8cabbc4d1482f6a5e2acc25a8f934681b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-98281 (GCVE-0-2026-98281)

Vulnerability from cvelistv5 – Published: 2026-10-06 08:45 – Updated: 2026-10-07 06:49

Title

futex: Also allocate private hash on vfork()

Summary

In the Linux kernel, the following vulnerability has been resolved: futex: Also allocate private hash on vfork() As Jann demonstrated, it is entirely feasible to access the mm through vfork(). Therefore we need to allocate a private hash on vfork() as well as any other CLONE_VM user. Specifically, it must be avoided to have (private) futex waiters before allocating the private hash.

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 Scorecard

References

3 references

URL	Tags
https://git.kernel.org/stable/c/5468a4855b63b3015…
https://git.kernel.org/stable/c/eecbafa8cabbc4d14…
https://git.kernel.org/stable/c/b61b6f95d6722ddbb…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1dcd36420af2da5bd59306dba9caf78e3d248b1d , < 5468a4855b63b30156a79e5248e01bf1a2c18dd7 (git) Affected: ee9dce44362b2d8132c32964656ab6dff7dfbc6a , < eecbafa8cabbc4d1482f6a5e2acc25a8f934681b (git) Affected: ee9dce44362b2d8132c32964656ab6dff7dfbc6a , < b61b6f95d6722ddbbbd09e689fa41b55fd36f9a5 (git) Affected: 974ac49a9a068b0591a59f65c63eb06579a13091 (git) Affected: 6.18.33 , < 6.18.54 (semver) Affected: 7.0.10 , < 7.1 (semver)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 6.18.54 , ≤ 6.18.* (semver) Unaffected: 7.2.8 , ≤ 7.2.* (semver) Unaffected: 7.3-rc4 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/fork.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5468a4855b63b30156a79e5248e01bf1a2c18dd7",
              "status": "affected",
              "version": "1dcd36420af2da5bd59306dba9caf78e3d248b1d",
              "versionType": "git"
            },
            {
              "lessThan": "eecbafa8cabbc4d1482f6a5e2acc25a8f934681b",
              "status": "affected",
              "version": "ee9dce44362b2d8132c32964656ab6dff7dfbc6a",
              "versionType": "git"
            },
            {
              "lessThan": "b61b6f95d6722ddbbbd09e689fa41b55fd36f9a5",
              "status": "affected",
              "version": "ee9dce44362b2d8132c32964656ab6dff7dfbc6a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "974ac49a9a068b0591a59f65c63eb06579a13091",
              "versionType": "git"
            },
            {
              "lessThan": "6.18.54",
              "status": "affected",
              "version": "6.18.33",
              "versionType": "semver"
            },
            {
              "lessThan": "7.1",
              "status": "affected",
              "version": "7.0.10",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/fork.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.54",
                  "versionStartIncluding": "6.18.33",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.8",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc4",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "7.0.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Also allocate private hash on vfork()\n\nAs Jann demonstrated, it is entirely feasible to access the mm through vfork().\nTherefore we need to allocate a private hash on vfork() as well as any other\nCLONE_VM user.\n\nSpecifically, it must be avoided to have (private) futex waiters before\nallocating the private hash."
        }
      ],
      "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 - The trigger is a local process calling vfork()/clone3(CLONE_VM|CLONE_VFORK) in kernel_clone()/copy_process(), where need_futex_hash_allocate_default() skipped the private hash, followed by futex() syscalls on the shared mm. No remote peer supplies any input.\nAC:L - The attacker owns every task involved: the vfork parent (killed through its TASK_KILLABLE wait_for_vfork_done, so its futex exit path runs on the shared mm) and the vfork child, which creates a thread to publish the first private hash. Both sides of the race are under attacker control, so it can be retried at will.\nPR:L - vfork, clone, futex(FUTEX_WAIT/LOCK_PI), robust lists and kill() all work for an ordinary unprivileged user with no capability checks. The hash allocation in futex_hash_allocate_default() has no privilege gate either.\nUI:N - The attacker\u0027s own processes create the shared-mm state and the futex operations. No other user has to do anything.\nS:U - The damaged objects are kernel futex state (mm-\u003efutex.phash, hash buckets, pi_state) inside the same kernel security authority. No guest/host or IOMMU boundary is crossed.\nC:H - __futex_pivot_hash() leaves waiters queued in the global hash when the private hash is first published, so later PI/requeue operations take a different bucket lock. Futex PI state handled under two different bucket locks is the classic futex use-after-free pattern, and the earlier bug from this same assumption was a KASAN use-after-free, so kernel memory disclosure is plausible.\nI:H - A freed pi_state or private-hash reference that the attacker can reallocate gives a kernel heap write primitive, as in earlier futex PI use-after-free exploits, so local privilege escalation is possible.\nA:H - Waiters stranded in the global hash miss every later wake that goes to the private bucket, which hangs the affected tasks. The pi_state/reference corruption from inconsistent bucket locking can cause a KASAN splat or kernel oops."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-07T06:49:52.329Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5468a4855b63b30156a79e5248e01bf1a2c18dd7"
        },
        {
          "url": "https://git.kernel.org/stable/c/eecbafa8cabbc4d1482f6a5e2acc25a8f934681b"
        },
        {
          "url": "https://git.kernel.org/stable/c/b61b6f95d6722ddbbbd09e689fa41b55fd36f9a5"
        }
      ],
      "title": "futex: Also allocate private hash on vfork()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98281",
    "datePublished": "2026-10-06T08:45:40.719Z",
    "dateReserved": "2026-09-25T10:25:14.335Z",
    "dateUpdated": "2026-10-07T06:49:52.329Z",
    "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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-FWJP-32V8-7PP8

CVE-2026-98281 (GCVE-0-2026-98281)

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