Vulnerability-Lookup

FKIE_CVE-2026-68399

Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-17 06:17

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: bpf: Fix UAF in sock clone early bailouts Similar to recent commit 9b51a6155d14 ("bpf,fork: wipe ->bpf_storage before bailouts that access it"), sk_clone() performs an initial shallow copy of the socket field ->sk_bpf_storage via sock_copy() for the cloned socket newsk. If sk_clone() bails out early (e.g. if sk_filter_charge() fails) prior to calling bpf_sk_storage_clone(), newsk->sk_bpf_storage still points to the parent socket's BPF local storage. When newsk is subsequently freed via sk_free(), the deallocation path (__sk_destruct() -> bpf_sk_storage_free()) destroys the parent socket's BPF local storage, leading to a use-after-free (UAF) on the parent socket. Fix this by resetting newsk->sk_bpf_storage to NULL immediately after sock_copy() in sk_clone(), and remove the now redundant initialization from bpf_sk_storage_clone().

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/14b49b5ab29979552c219a09e569b424fbbf4a6e
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/core/bpf_sk_storage.c",
            "net/core/sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "14b49b5ab29979552c219a09e569b424fbbf4a6e",
              "status": "affected",
              "version": "6ac99e8f23d4b10258406ca0dd7bffca5f31da9d",
              "versionType": "git"
            },
            {
              "lessThan": "7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f",
              "status": "affected",
              "version": "6ac99e8f23d4b10258406ca0dd7bffca5f31da9d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/core/bpf_sk_storage.c",
            "net/core/sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.2"
            },
            {
              "lessThan": "5.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "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\nbpf: Fix UAF in sock clone early bailouts\n\nSimilar to recent commit 9b51a6155d14 (\"bpf,fork: wipe -\u003ebpf_storage\nbefore bailouts that access it\"), sk_clone() performs an initial\nshallow copy of the socket field -\u003esk_bpf_storage via sock_copy()\nfor the cloned socket newsk.\n\nIf sk_clone() bails out early (e.g. if sk_filter_charge() fails) prior\nto calling bpf_sk_storage_clone(), newsk-\u003esk_bpf_storage still points\nto the parent socket\u0027s BPF local storage. When newsk is subsequently\nfreed via sk_free(), the deallocation path (__sk_destruct() -\u003e\nbpf_sk_storage_free()) destroys the parent socket\u0027s BPF local storage,\nleading to a use-after-free (UAF) on the parent socket.\n\nFix this by resetting newsk-\u003esk_bpf_storage to NULL immediately after\nsock_copy() in sk_clone(), and remove the now redundant initialization\nfrom bpf_sk_storage_clone()."
    }
  ],
  "id": "CVE-2026-68399",
  "lastModified": "2026-08-17T06:17:48.670",
  "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": "2026-08-10T13:20:33.383",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/14b49b5ab29979552c219a09e569b424fbbf4a6e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-68399 (GCVE-0-2026-68399)

Vulnerability from cvelistv5 – Published: 2026-08-10 12:04 – Updated: 2026-08-17 05:04

Title

bpf: Fix UAF in sock clone early bailouts

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

2 references

URL	Tags
https://git.kernel.org/stable/c/14b49b5ab29979552…
https://git.kernel.org/stable/c/7cbd0c4cebe4c9f67…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 6ac99e8f23d4b10258406ca0dd7bffca5f31da9d , < 14b49b5ab29979552c219a09e569b424fbbf4a6e (git) Affected: 6ac99e8f23d4b10258406ca0dd7bffca5f31da9d , < 7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f (git)
Linux	Linux	Affected: 5.2 Unaffected: 0 , < 5.2 (semver) Unaffected: 7.1.6 , ≤ 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/core/bpf_sk_storage.c",
            "net/core/sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "14b49b5ab29979552c219a09e569b424fbbf4a6e",
              "status": "affected",
              "version": "6ac99e8f23d4b10258406ca0dd7bffca5f31da9d",
              "versionType": "git"
            },
            {
              "lessThan": "7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f",
              "status": "affected",
              "version": "6ac99e8f23d4b10258406ca0dd7bffca5f31da9d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/core/bpf_sk_storage.c",
            "net/core/sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.2"
            },
            {
              "lessThan": "5.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "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": "7.1.6",
                  "versionStartIncluding": "5.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "5.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix UAF in sock clone early bailouts\n\nSimilar to recent commit 9b51a6155d14 (\"bpf,fork: wipe -\u003ebpf_storage\nbefore bailouts that access it\"), sk_clone() performs an initial\nshallow copy of the socket field -\u003esk_bpf_storage via sock_copy()\nfor the cloned socket newsk.\n\nIf sk_clone() bails out early (e.g. if sk_filter_charge() fails) prior\nto calling bpf_sk_storage_clone(), newsk-\u003esk_bpf_storage still points\nto the parent socket\u0027s BPF local storage. When newsk is subsequently\nfreed via sk_free(), the deallocation path (__sk_destruct() -\u003e\nbpf_sk_storage_free()) destroys the parent socket\u0027s BPF local storage,\nleading to a use-after-free (UAF) on the parent socket.\n\nFix this by resetting newsk-\u003esk_bpf_storage to NULL immediately after\nsock_copy() in sk_clone(), and remove the now redundant initialization\nfrom bpf_sk_storage_clone()."
        }
      ],
      "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 clone path and its early-bailout condition are driven through the BPF sk_storage subsystem and local socket setup (attaching sk_storage, attaching a socket filter, adjusting optmem_max). Per kernel guidance BPF is Local; a remote peer cannot control the bailout conditions.\nAC:L - An attacker who controls the local setup can deterministically force the early bailout by attaching a filter and lowering net.core.optmem_max below the filter size, exactly the sysctl-change scenario the code documents, making sk_filter_charge fail on every clone.\nPR:L - Reaching the bug requires attaching BPF sk_storage and manipulating socket/net settings; these capabilities (CAP_BPF/CAP_NET_ADMIN) can be reachable via user namespaces in some configurations, so the lower-privilege value is chosen per the higher-severity rule.\nUI:N - The clone is triggered by connection acceptance or association creation with no victim action; no user interaction is needed.\nS:U - The UAF corrupts kernel socket/BPF-storage objects within the kernel\u0027s own security authority; no crossing into a separate security scope (no VM/IOMMU boundary).\nC:H - The use-after-free lets the attacker reclaim the freed bpf_local_storage object with controlled contents, enabling disclosure of kernel memory; per guidance UAF is High.\nI:H - UAF on a live socket\u0027s BPF storage enables heap grooming and arbitrary-write primitives, giving control-flow hijack potential; per guidance UAF is High.\nA:H - Destroying the parent socket\u0027s still-referenced BPF local storage reliably causes memory corruption, oops, and kernel panic; per guidance any UAF/crash is High."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:04:47.842Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/14b49b5ab29979552c219a09e569b424fbbf4a6e"
        },
        {
          "url": "https://git.kernel.org/stable/c/7cbd0c4cebe4c9f678d15e6b9ba975e1155a107f"
        }
      ],
      "title": "bpf: Fix UAF in sock clone early bailouts",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68399",
    "datePublished": "2026-08-10T12:04:18.837Z",
    "dateReserved": "2026-07-30T09:28:09.389Z",
    "dateUpdated": "2026-08-17T05:04:47.842Z",
    "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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