Vulnerability-Lookup

GHSA-FQG3-P6V9-G3WX

Vulnerability from github – Published: 2026-04-24 15:32 – Updated: 2026-04-27 15:30

Details

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

futex: Require sys_futex_requeue() to have identical flags

Nicholas reported that his LLM found it was possible to create a UaF when sys_futex_requeue() is used with different flags. The initial motivation for allowing different flags was the variable sized futex, but since that hasn't been merged (yet), simply mandate the flags are identical, as is the case for the old style sys_futex() requeue operations.

Severity

7.8 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-31554"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-24T15:16:29Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Require sys_futex_requeue() to have identical flags\n\nNicholas reported that his LLM found it was possible to create a UaF\nwhen sys_futex_requeue() is used with different flags. The initial\nmotivation for allowing different flags was the variable sized futex,\nbut since that hasn\u0027t been merged (yet), simply mandate the flags are\nidentical, as is the case for the old style sys_futex() requeue\noperations.",
  "id": "GHSA-fqg3-p6v9-g3wx",
  "modified": "2026-04-27T15:30:42Z",
  "published": "2026-04-24T15:32:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31554"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/027145ace09fad4c7cbcd6c61fe9b429c63eb0e5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/18b7d09c2b794c71d4252f3ea2cf84ad12b73d6a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/19f94b39058681dec64a10ebeb6f23fe7fc3f77a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e2f78c7ec1655fedd945366151ba54fcb9580508"
    }
  ],
  "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-2026-31554 (GCVE-0-2026-31554)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:35 – Updated: 2026-08-05 12:23

Title

futex: Require sys_futex_requeue() to have identical flags

Summary

In the Linux kernel, the following vulnerability has been resolved: futex: Require sys_futex_requeue() to have identical flags Nicholas reported that his LLM found it was possible to create a UaF when sys_futex_requeue() is used with different flags. The initial motivation for allowing different flags was the variable sized futex, but since that hasn't been merged (yet), simply mandate the flags are identical, as is the case for the old style sys_futex() requeue operations.

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

4 references

URL	Tags
https://git.kernel.org/stable/c/027145ace09fad4c7…
https://git.kernel.org/stable/c/18b7d09c2b794c71d…
https://git.kernel.org/stable/c/e2f78c7ec1655fedd…
https://git.kernel.org/stable/c/19f94b39058681dec…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 0f4b5f972216782a4acb1ae00dcb55173847c2ff , < 027145ace09fad4c7cbcd6c61fe9b429c63eb0e5 (git) Affected: 0f4b5f972216782a4acb1ae00dcb55173847c2ff , < 18b7d09c2b794c71d4252f3ea2cf84ad12b73d6a (git) Affected: 0f4b5f972216782a4acb1ae00dcb55173847c2ff , < e2f78c7ec1655fedd945366151ba54fcb9580508 (git) Affected: 0f4b5f972216782a4acb1ae00dcb55173847c2ff , < 19f94b39058681dec64a10ebeb6f23fe7fc3f77a (git)
Linux	Linux	Affected: 6.7 Unaffected: 0 , < 6.7 (semver) Unaffected: 6.12.80 , ≤ 6.12.* (semver) Unaffected: 6.18.21 , ≤ 6.18.* (semver) Unaffected: 6.19.11 , ≤ 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": [
            "kernel/futex/syscalls.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "027145ace09fad4c7cbcd6c61fe9b429c63eb0e5",
              "status": "affected",
              "version": "0f4b5f972216782a4acb1ae00dcb55173847c2ff",
              "versionType": "git"
            },
            {
              "lessThan": "18b7d09c2b794c71d4252f3ea2cf84ad12b73d6a",
              "status": "affected",
              "version": "0f4b5f972216782a4acb1ae00dcb55173847c2ff",
              "versionType": "git"
            },
            {
              "lessThan": "e2f78c7ec1655fedd945366151ba54fcb9580508",
              "status": "affected",
              "version": "0f4b5f972216782a4acb1ae00dcb55173847c2ff",
              "versionType": "git"
            },
            {
              "lessThan": "19f94b39058681dec64a10ebeb6f23fe7fc3f77a",
              "status": "affected",
              "version": "0f4b5f972216782a4acb1ae00dcb55173847c2ff",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/futex/syscalls.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.80",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.11",
              "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": "6.12.80",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.21",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.11",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Require sys_futex_requeue() to have identical flags\n\nNicholas reported that his LLM found it was possible to create a UaF\nwhen sys_futex_requeue() is used with different flags. The initial\nmotivation for allowing different flags was the variable sized futex,\nbut since that hasn\u0027t been merged (yet), simply mandate the flags are\nidentical, as is the case for the old style sys_futex() requeue\noperations."
        }
      ],
      "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 vulnerable code is reached through the local futex_requeue syscall path, not through network, adjacent, or physical input.\nAC:L - An unprivileged attacker can create the needed futex waiters, choose mismatched source and destination flags, and control the requeue/lifetime sequence; any race or timing is attacker-controlled.\nPR:L - The syscall has no capability or namespace gate, but the attacker needs basic local code execution to invoke futex syscalls and arrange the participating tasks.\nUI:N - No victim action is required; the attacker can trigger the vulnerable futex operations from their own processes/threads.\nS:U - The impact is within the kernel/local system security authority and is a standard local kernel memory corruption or privilege escalation scenario.\nC:H - The bug is a kernel use-after-free caused by requeueing waiters across incompatible private/shared futex hash lifetimes, which can plausibly be shaped into kernel memory disclosure.\nI:H - The use-after-free involves kernel heap/list/lock state reachable from attacker-controlled futex operations, making arbitrary kernel memory corruption or control-flow impact defensible.\nA:H - Even without full exploitation, dereferencing and manipulating freed futex hash bucket state can crash or hang the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:23:28.646Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/027145ace09fad4c7cbcd6c61fe9b429c63eb0e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/18b7d09c2b794c71d4252f3ea2cf84ad12b73d6a"
        },
        {
          "url": "https://git.kernel.org/stable/c/e2f78c7ec1655fedd945366151ba54fcb9580508"
        },
        {
          "url": "https://git.kernel.org/stable/c/19f94b39058681dec64a10ebeb6f23fe7fc3f77a"
        }
      ],
      "title": "futex: Require sys_futex_requeue() to have identical flags",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31554",
    "datePublished": "2026-04-24T14:35:38.527Z",
    "dateReserved": "2026-03-09T15:48:24.115Z",
    "dateUpdated": "2026-08-05T12:23:28.646Z",
    "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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-FQG3-P6V9-G3WX

CVE-2026-31554 (GCVE-0-2026-31554)

Tags

Sightings

Nomenclature

Related by attack behaviour