{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "901271e0403af638c224987c2a4e55cebade7e91"
            },
            {
              "fixed": "8bfdfe0dbb36a650b7c4dec1aeae078319938a0b"
            },
            {
              "fixed": "dc4b577a083b361d25e118dc96d8281255ebe22c"
            },
            {
              "fixed": "dfdfd987f1917c84766e097a6120a1f3f1634940"
            },
            {
              "fixed": "f02334a9e378f7e07232b26dc3d2ab353339f040"
            },
            {
              "fixed": "f4013598b69457dbea350df52e52daea6faef8eb"
            },
            {
              "fixed": "1b8fb5a20508bfb0db854e01214888c761b3a911"
            },
            {
              "fixed": "c1cda72f6acec02ebd45d913bf8527ff77336ba6"
            },
            {
              "fixed": "9f29cd8a8e7901a2617c8064ce9f50fc67b97cb8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.18.0"
            },
            {
              "fixed": "5.10.265"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.148"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.101"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.42"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68297.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix u16 MTU truncation in media and bearer MTU validation\n\nBoth TIPC_NL_MEDIA_SET and TIPC_NL_BEARER_SET accept user-supplied\nMTU values but only enforce a minimum bound, not a maximum. When a user\nsets the MTU to a value exceeding U16_MAX (65535), it passes validation\nbut is silently truncated when assigned to u16 fields l-\u003emtu and\nl-\u003eadvertised_mtu in tipc_link_create(). Values like 65536 (0x10000)\ntruncate to 0, causing a division by zero in tipc_link_set_queue_limits()\nwhich computes TIPC_MAX_PUBL / (l-\u003emtu / ITEM_SIZE). Other overflowing\nvalues (e.g. 65537-131071) produce small incorrect MTU values, resulting\nin link malfunction behaviors.\n\nCrash stack (triggered as unprivileged user via user namespace):\n\n  tipc_link_set_queue_limits  net/tipc/link.c:2531\n  tipc_link_create            net/tipc/link.c:520\n  tipc_node_check_dest        net/tipc/node.c:1279\n  tipc_disc_rcv               net/tipc/discover.c:252\n  tipc_rcv                    net/tipc/node.c:2129\n  tipc_udp_recv               net/tipc/udp_media.c:392\n\nTwo independent paths lack the upper bound check:\n1. tipc_udp_mtu_bad() -- called from __tipc_nl_media_set() (MEDIA_SET)\n2. inline check in __tipc_nl_bearer_set() at bearer.c:1160 (BEARER_SET)\n\nFix both by rejecting MTU values above U16_MAX.",
  "id": "CVE-2026-68297",
  "modified": "2026-08-21T03:30:30.717379066Z",
  "published": "2026-08-10T12:02:30.721Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1b8fb5a20508bfb0db854e01214888c761b3a911"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8bfdfe0dbb36a650b7c4dec1aeae078319938a0b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9f29cd8a8e7901a2617c8064ce9f50fc67b97cb8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c1cda72f6acec02ebd45d913bf8527ff77336ba6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dc4b577a083b361d25e118dc96d8281255ebe22c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dfdfd987f1917c84766e097a6120a1f3f1634940"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f02334a9e378f7e07232b26dc3d2ab353339f040"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f4013598b69457dbea350df52e52daea6faef8eb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68297.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68297"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "tipc: fix u16 MTU truncation in media and bearer MTU validation"
}