{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "55e007fc3b4d76fa4d6b4660f6904fe6ab045a1b"
            },
            {
              "fixed": "5aca8e6a8ff6aeae358c1d9b65447aac416ace95"
            },
            {
              "fixed": "4ba1f57313f36a3ce6f77d593548f0c511f34aa1"
            },
            {
              "fixed": "ca797491f0ae4bfde9039f79f6f1ed7781c9110f"
            },
            {
              "fixed": "cfba0f45553de2b803059e3d539a1e418df24da8"
            },
            {
              "fixed": "c7ee4bea64f559ea8e03260014775b64c720cb5b"
            },
            {
              "fixed": "90d51095371d96747f45bbd8504edf6513e039ef"
            },
            {
              "fixed": "cd5dd68267c4238795fadaf02b3575ca3f8a6500"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "5.10.271"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.222"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.189"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.158"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.55"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98554.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvlan: ensure sufficient headroom in vlan_dev_hard_header()\n\nCallers that only reserve ETH_HLEN or less (such as llc_alloc_frame()),\nor skbs allocated before dynamic device/headroom changes (e.g. toggling\nVLAN_FLAG_REORDER_HDR or bonding/team switching slaves), can reach\nvlan_dev_hard_header() with insufficient headroom and trigger\nskb_under_panic().\n\nUse skb_cow_head() in vlan_dev_hard_header() when VLAN_FLAG_REORDER_HDR\nis not set to ensure sufficient headroom for the VLAN header(s) and the\nunderlying device hard header.\n\nUse READ_ONCE() to read dev-\u003ehard_header_len and dev-\u003eneeded_headroom as\nthey can be updated concurrently under RTNL (e.g. in\nvlan_transfer_features()) while vlan_dev_hard_header() runs locklessly on\nthe transmit path. Also avoid LL_RESERVED_SPACE(dev) here so that the\nextra HH_DATA_MOD alignment padding does not trigger unnecessary\npskb_expand_head() reallocations on inner stacked VLAN devices after the\nouter VLAN header has been pushed.",
  "id": "CVE-2026-98554",
  "modified": "2026-10-20T02:31:03.228901585Z",
  "published": "2026-10-18T15:18:21.751Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4ba1f57313f36a3ce6f77d593548f0c511f34aa1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55e007fc3b4d76fa4d6b4660f6904fe6ab045a1b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5aca8e6a8ff6aeae358c1d9b65447aac416ace95"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/90d51095371d96747f45bbd8504edf6513e039ef"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7ee4bea64f559ea8e03260014775b64c720cb5b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ca797491f0ae4bfde9039f79f6f1ed7781c9110f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd5dd68267c4238795fadaf02b3575ca3f8a6500"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cfba0f45553de2b803059e3d539a1e418df24da8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98554.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98554"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "vlan: ensure sufficient headroom in vlan_dev_hard_header()"
}