Vulnerability-Lookup

FKIE_CVE-2026-64576

Vulnerability from fkie_nvd - Published: 2026-08-05 08:16 - Updated: 2026-08-08 15:16

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: nexthop: initialize extack in nh_res_bucket_migrate() nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to call_nexthop_res_bucket_notifiers(). When nh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns -ENOMEM), the error is propagated back before any notifier sets extack._msg, and the error path formats the stale pointer with pr_err_ratelimited("%s\n", extack._msg). With CONFIG_INIT_STACK_NONE this dereferences uninitialized stack memory: Oops: general protection fault, probably for non-canonical address ... KASAN: maybe wild-memory-access in range [...] RIP: 0010:string (lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) _printk (kernel/printk/printk.c:2504) nh_res_bucket_migrate (net/ipv4/nexthop.c:1816) nh_res_table_upkeep (net/ipv4/nexthop.c:1866) rtm_new_nexthop (net/ipv4/nexthop.c:3323) rtnetlink_rcv_msg (net/core/rtnetlink.c:7076) netlink_sendmsg (net/netlink/af_netlink.c:1900) Kernel panic - not syncing: Fatal exception Zero-initialize extack so _msg is NULL on error paths that never set it.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/nexthop.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c0936c131a71657afc635d0db2ab096d15d473e1",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "d536bf205c71f700f6de2086038c3e1d77724715",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "18506d7263768d76ac8e057ba55a4d9da50aad66",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "6347c5314cee49f364aaf2e40ff15415a57a116e",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/nexthop.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc5",
              "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\nnexthop: initialize extack in nh_res_bucket_migrate()\n\nnh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to\ncall_nexthop_res_bucket_notifiers(). When\nnh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns\n-ENOMEM), the error is propagated back before any notifier sets\nextack._msg, and the error path formats the stale pointer with\npr_err_ratelimited(\"%s\\n\", extack._msg). With CONFIG_INIT_STACK_NONE\nthis dereferences uninitialized stack memory:\n\n  Oops: general protection fault, probably for non-canonical address ...\n  KASAN: maybe wild-memory-access in range [...]\n  RIP: 0010:string (lib/vsprintf.c:730)\n   vsnprintf (lib/vsprintf.c:2945)\n   _printk (kernel/printk/printk.c:2504)\n   nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)\n   nh_res_table_upkeep (net/ipv4/nexthop.c:1866)\n   rtm_new_nexthop (net/ipv4/nexthop.c:3323)\n   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)\n   netlink_sendmsg (net/netlink/af_netlink.c:1900)\n  Kernel panic - not syncing: Fatal exception\n\nZero-initialize extack so _msg is NULL on error paths that never set it."
    }
  ],
  "id": "CVE-2026-64576",
  "lastModified": "2026-08-08T15:16:32.537",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-05T08:16:37.483",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-64576 (GCVE-0-2026-64576)

Vulnerability from cvelistv5 – Published: 2026-08-05 08:09 – Updated: 2026-08-08 15:13

Title

nexthop: initialize extack in nh_res_bucket_migrate()

Summary

Severity

7.1 (High)


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

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/c0936c131a71657af…
https://git.kernel.org/stable/c/3081702ea5aca0aee…
https://git.kernel.org/stable/c/d536bf205c71f700f…
https://git.kernel.org/stable/c/18506d7263768d76a…
https://git.kernel.org/stable/c/6347c5314cee49f36…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 7c37c7e00411b3d1e0c5292368317aca69d1f324 , < c0936c131a71657afc635d0db2ab096d15d473e1 (git) Affected: 7c37c7e00411b3d1e0c5292368317aca69d1f324 , < 3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d (git) Affected: 7c37c7e00411b3d1e0c5292368317aca69d1f324 , < d536bf205c71f700f6de2086038c3e1d77724715 (git) Affected: 7c37c7e00411b3d1e0c5292368317aca69d1f324 , < 18506d7263768d76ac8e057ba55a4d9da50aad66 (git) Affected: 7c37c7e00411b3d1e0c5292368317aca69d1f324 , < 6347c5314cee49f364aaf2e40ff15415a57a116e (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2-rc5 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/nexthop.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c0936c131a71657afc635d0db2ab096d15d473e1",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "d536bf205c71f700f6de2086038c3e1d77724715",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "18506d7263768d76ac8e057ba55a4d9da50aad66",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            },
            {
              "lessThan": "6347c5314cee49f364aaf2e40ff15415a57a116e",
              "status": "affected",
              "version": "7c37c7e00411b3d1e0c5292368317aca69d1f324",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/nexthop.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc5",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.148",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc5",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: initialize extack in nh_res_bucket_migrate()\n\nnh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to\ncall_nexthop_res_bucket_notifiers(). When\nnh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns\n-ENOMEM), the error is propagated back before any notifier sets\nextack._msg, and the error path formats the stale pointer with\npr_err_ratelimited(\"%s\\n\", extack._msg). With CONFIG_INIT_STACK_NONE\nthis dereferences uninitialized stack memory:\n\n  Oops: general protection fault, probably for non-canonical address ...\n  KASAN: maybe wild-memory-access in range [...]\n  RIP: 0010:string (lib/vsprintf.c:730)\n   vsnprintf (lib/vsprintf.c:2945)\n   _printk (kernel/printk/printk.c:2504)\n   nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)\n   nh_res_table_upkeep (net/ipv4/nexthop.c:1866)\n   rtm_new_nexthop (net/ipv4/nexthop.c:3323)\n   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)\n   netlink_sendmsg (net/netlink/af_netlink.c:1900)\n  Kernel panic - not syncing: Fatal exception\n\nZero-initialize extack so _msg is NULL on error paths that never set it."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Triggered via local RTM_NEWNEXTHOP over rtnetlink (sendmsg \u2192 rtnetlink_rcv_msg \u2192 rtm_new_nexthop \u2192 nh_res_table_upkeep \u2192 nh_res_bucket_migrate), not by processing remote packets.\nAC:L - An attacker can create resilient nexthop groups, ensure notifiers are registered (e.g. VXLAN pernet init), force bucket migration, and induce the kzalloc -ENOMEM path; stack contents are groomable, with no attacker-independent condition required.\nPR:L - rtnetlink_rcv_msg requires CAP_NET_ADMIN via netlink_net_capable() against the socket netns user_ns, which an unprivileged user obtains with unshare -Urn, so privileges are Low not High.\nUI:N - The attacker issues the netlink nexthop configuration and triggers migration themselves; no victim action is required.\nS:U - Impact stays within the host kernel networking authority; this is a local DoS/disclosure bug, not a VM escape, IOMMU bypass, or other cross-boundary scope change.\nC:H - pr_err_ratelimited(\"%s\") dereferences an uninitialized extack._msg pointer as a C string, enabling an attacker-groomable wild kernel read into the log, consistent with treating unbounded wild/OOB reads as Confidentiality High.\nI:N - The defect only reads through the stale _msg pointer for printing; there is no write, free, or other memory-corruption integrity primitive.\nA:H - The wild %s dereference causes a general protection fault / KASAN wild-memory-access and kernel panic, as shown in the fix commit report, so Availability is High."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-08T15:13:13.892Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1"
        },
        {
          "url": "https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d"
        },
        {
          "url": "https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715"
        },
        {
          "url": "https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66"
        },
        {
          "url": "https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e"
        }
      ],
      "title": "nexthop: initialize extack in nh_res_bucket_migrate()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64576",
    "datePublished": "2026-08-05T08:09:32.529Z",
    "dateReserved": "2026-07-19T15:36:31.798Z",
    "dateUpdated": "2026-08-08T15:13:13.892Z",
    "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.

Action not permitted

FKIE_CVE-2026-64576

CVE-2026-64576 (GCVE-0-2026-64576)

Tags

Sightings

Nomenclature