{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "456b61bca8ee324ab6c18b065e632c9a8c88aa39"
            },
            {
              "fixed": "2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6"
            },
            {
              "fixed": "0c8f56c583c3250408367880c98e4d6fbc929315"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.38"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98099.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: mcast: use rcu_assign_pointer() for __rcu list updates\n\nSeveral places in net/ipv6/mcast.c update RCU-protected lists\n(np-\u003eipv6_mc_list, idev-\u003emc_list, idev-\u003emc_tomb) using direct pointer\nassignments instead of rcu_assign_pointer():\n\n1. In __ipv6_dev_mc_dec(), unlinking a group from idev-\u003emc_list did:\n       *map = ma-\u003enext;\n   without rcu_assign_pointer() while concurrent readers traverse\n   idev-\u003emc_list locklessly under rcu_read_lock().\n2. In ipv6_sock_mc_drop() and __ipv6_sock_mc_close(), unlinking a group\n   from np-\u003eipv6_mc_list directly assigned *lnk = mc_lst-\u003enext and\n   np-\u003eipv6_mc_list = mc_lst-\u003enext without rcu_assign_pointer(), racing\n   with lockless readers in inet6_mc_check().\n3. In __ipv6_sock_mc_join(), mc_lst-\u003enext was initialized to\n   np-\u003eipv6_mc_list via raw assignment before publishing mc_lst.\n4. In mld_del_delrec() and __ipv6_dev_mc_inc(), __rcu source pointers\n   passed into rcu_assign_pointer() lacked explicit dereference helpers.\n\nFix these by consistently using rcu_assign_pointer() along with\nmc_dereference() / sock_dereference().",
  "id": "CVE-2026-98099",
  "modified": "2026-09-27T03:30:26.486571146Z",
  "published": "2026-09-25T10:24:28.929Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0c8f56c583c3250408367880c98e4d6fbc929315"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2e46b0c9fcf7e10b64ce1630b925f47918d1f7f6"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98099.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98099"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ipv6: mcast: use rcu_assign_pointer() for __rcu list updates"
}