Vulnerability-Lookup

GHSA-V693-V3PX-MXPC

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

bpf: Preserve pointer spill metadata during half-slot cleanup

__clean_func_state() cleans dead stack slots in 4-byte halves. When the high half of a STACK_SPILL slot is dead and the low half remains live, cleanup converts the live low half to STACK_MISC or STACK_ZERO and clears the saved spilled_ptr metadata.

That conversion is safe only for scalar spills. For a pointer spill, this metadata clear lets a later 32-bit fill from the still-live half avoid the normal non-scalar register-fill check and be treated as an ordinary scalar stack read.

Leave non-scalar spill slots intact in this half-live shape. This is conservative for pruning and preserves the existing check_stack_read_fixed_off() rejection path for partial fills from pointer spills.

Severity

8.4 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-72426"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:16Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve pointer spill metadata during half-slot cleanup\n\n__clean_func_state() cleans dead stack slots in 4-byte halves. When the\nhigh half of a STACK_SPILL slot is dead and the low half remains live,\ncleanup converts the live low half to STACK_MISC or STACK_ZERO and clears\nthe saved spilled_ptr metadata.\n\nThat conversion is safe only for scalar spills. For a pointer spill, this\nmetadata clear lets a later 32-bit fill from the still-live half avoid the\nnormal non-scalar register-fill check and be treated as an ordinary scalar\nstack read.\n\nLeave non-scalar spill slots intact in this half-live shape. This is\nconservative for pruning and preserves the existing\ncheck_stack_read_fixed_off() rejection path for partial fills from pointer\nspills.",
  "id": "GHSA-v693-v3px-mxpc",
  "modified": "2026-08-17T06:33:29Z",
  "published": "2026-08-15T06:32:23Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72426"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f9278b22cda6fd2525049930157b79b4036b4ef"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3a354149bceacadbcf7d7b4766f5ef26a85892ab"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-72426 (GCVE-0-2026-72426)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:56 – Updated: 2026-08-17 05:44

Title

bpf: Preserve pointer spill metadata during half-slot cleanup

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Preserve pointer spill metadata during half-slot cleanup __clean_func_state() cleans dead stack slots in 4-byte halves. When the high half of a STACK_SPILL slot is dead and the low half remains live, cleanup converts the live low half to STACK_MISC or STACK_ZERO and clears the saved spilled_ptr metadata. That conversion is safe only for scalar spills. For a pointer spill, this metadata clear lets a later 32-bit fill from the still-live half avoid the normal non-scalar register-fill check and be treated as an ordinary scalar stack read. Leave non-scalar spill slots intact in this half-live shape. This is conservative for pruning and preserves the existing check_stack_read_fixed_off() rejection path for partial fills from pointer spills.

Severity

8.4 (High)


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

Assigner

Linux mitre root Scorecard

References

2 references

URL	Tags
https://git.kernel.org/stable/c/0f9278b22cda6fd25…
https://git.kernel.org/stable/c/3a354149bceacadbc…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: be23266b4a08540aa43d8503a2ea10247c8daebe , < 0f9278b22cda6fd2525049930157b79b4036b4ef (git) Affected: be23266b4a08540aa43d8503a2ea10247c8daebe , < 3a354149bceacadbcf7d7b4766f5ef26a85892ab (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/states.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0f9278b22cda6fd2525049930157b79b4036b4ef",
              "status": "affected",
              "version": "be23266b4a08540aa43d8503a2ea10247c8daebe",
              "versionType": "git"
            },
            {
              "lessThan": "3a354149bceacadbcf7d7b4766f5ef26a85892ab",
              "status": "affected",
              "version": "be23266b4a08540aa43d8503a2ea10247c8daebe",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/states.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": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "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": "7.1.5",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve pointer spill metadata during half-slot cleanup\n\n__clean_func_state() cleans dead stack slots in 4-byte halves. When the\nhigh half of a STACK_SPILL slot is dead and the low half remains live,\ncleanup converts the live low half to STACK_MISC or STACK_ZERO and clears\nthe saved spilled_ptr metadata.\n\nThat conversion is safe only for scalar spills. For a pointer spill, this\nmetadata clear lets a later 32-bit fill from the still-live half avoid the\nnormal non-scalar register-fill check and be treated as an ordinary scalar\nstack read.\n\nLeave non-scalar spill slots intact in this half-live shape. This is\nconservative for pruning and preserves the existing\ncheck_stack_read_fixed_off() rejection path for partial fills from pointer\nspills."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The flaw is reached only through the local bpf(BPF_PROG_LOAD) syscall during BPF verifier state pruning in bpf_is_state_visited()-\u003eclean_verifier_state()-\u003e__clean_func_state(), which is a local kernel interface per BPF CVSS guidance.\nAC:L - An attacker fully controls the crafted BPF bytecode, can spill a pointer, force verifier checkpoints (e.g., BPF_F_TEST_STATE_FREQ or branch pruning), and reliably trigger the half-slot cleanup path without races or external timing.\nPR:N - Exploitation occurs at BPF_PROG_LOAD via bpf(); on systems with kernel.unprivileged_bpf_disabled=0, unprivileged users can load socket-filter programs that trigger this verifier path without CAP_BPF or init-namespace root.\nUI:N - No victim interaction is required; the attacker loads and verifies their own malicious BPF program through the bpf() syscall.\nS:U - Impact is a BPF verifier bypass leading to kernel memory corruption and local privilege escalation within the same kernel security boundary, not a cross-authority escape such as VM guest-to-host.\nC:H - Cleared pointer spill metadata lets partial 32-bit fills bypass non-scalar register-fill checks, causing verifier/runtime type confusion that can be developed into arbitrary kernel memory disclosure primitives.\nI:H - Verifier-approved programs can treat pointer spill bytes as scalars and perform unsafe memory operations, enabling out-of-bounds writes and control-flow hijacking for arbitrary kernel code execution from BPF context.\nA:H - Executing verifier-incorrect BPF with confused pointer/scalar state can trigger kernel oops or panic, and the attacker can repeatedly load and run crafted programs to cause denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:44:06.105Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0f9278b22cda6fd2525049930157b79b4036b4ef"
        },
        {
          "url": "https://git.kernel.org/stable/c/3a354149bceacadbcf7d7b4766f5ef26a85892ab"
        }
      ],
      "title": "bpf: Preserve pointer spill metadata during half-slot cleanup",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72426",
    "datePublished": "2026-08-15T05:56:43.575Z",
    "dateReserved": "2026-08-09T03:40:39.928Z",
    "dateUpdated": "2026-08-17T05:44:06.105Z",
    "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.
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GHSA-V693-V3PX-MXPC

CVE-2026-72426 (GCVE-0-2026-72426)

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