{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "740d798e8767d8a449902b1a1bbc70facfce19b5"
            },
            {
              "fixed": "d4a67a880654e1bfe318a31bea0bdbb026a09ade"
            },
            {
              "fixed": "545616b4e7325be3c61fc082538cb06d14f7b1db"
            },
            {
              "fixed": "2ac7d6e620764f1fc79eb4edd3610a7a661981ca"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.13.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97566.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: kernel: drop pending ADD_ADDR when removing ID0\n\nThe in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement\nentry alive when removing the id 0 endpoint. This happens because the id 0\nremoval path does not tear down pending announcements, unlike the non-zero\nid path.\n\nWhen the PM later reselects id 0 after adding another signal endpoint, it\nfinds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel())\nin mptcp_pm_announced_alloc().\n\nRoot cause: asymmetry between removal paths.\n- Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls\n  mptcp_pm_remove_announced() to clean up.\n- Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely.\n\nFix by making the id 0 path symmetric: call mptcp_pm_announced_remove()\nand decrement add_addr_signaled before queuing the RM_ADDR.\n\nSubtle detail: signal endpoints are stored in anno_list with port 0, but\nmsk_local carries the connection's local port. In other words, entries\nlinked to ID0 paths should have port == 0. A follow-up patch will ensure\nthat. mptcp_pm_announced_remove() uses use_port=true for comparison. So\nclear the port before the lookup.",
  "id": "CVE-2026-97566",
  "modified": "2026-09-27T03:31:00.593135859Z",
  "published": "2026-09-25T10:21:53.068Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2ac7d6e620764f1fc79eb4edd3610a7a661981ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/545616b4e7325be3c61fc082538cb06d14f7b1db"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4a67a880654e1bfe318a31bea0bdbb026a09ade"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97566.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97566"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0"
}