{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "fe881ef11cf0220f118816181930494d484c4883"
            },
            {
              "fixed": "4b9bc21b2396c396d88dd909caaf73d5be6ff593"
            },
            {
              "fixed": "43efb1f997e976f386aa89716f55870cd2cff9ad"
            },
            {
              "fixed": "1eeec0c51fd5598da44080ed96bbd9880021c28b"
            },
            {
              "fixed": "1d664be4ca49d1696e85239236f4988dfc4653c3"
            },
            {
              "fixed": "97f907203321eee2cc9132d5c9eb47698fb41d35"
            },
            {
              "fixed": "40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f"
            },
            {
              "fixed": "c20f755338ca234e523dfc943719f194dfc1f903"
            },
            {
              "fixed": "2566866fc30965d915d0b52b5c3323b362619f0e"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "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-2026-98621.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gue: reject invalid REMCSUM offsets\n\nThe REMCSUM option carries an absolute checksum start and checksum field\noffset. gue_remcsum() passes them to skb_remcsum_process(), whose\npartial path stores offset - start in the u16 skb-\u003ecsum_offset variable.\nIf offset is less than start, this underflows.\n\nA forwarded packet can retain CHECKSUM_PARTIAL and reach a NETIF_F_HW_CSUM\ndriver which trusts the metadata, leading skb_copy_and_csum_dev() to write\ntwo bytes about 64 KiB beyond the destination buffer.\n\nReject reversed tuples in validate_gue_flags(), after the existing length\nvalidation, so all GUE parsers enforce the ordering in one place.",
  "id": "CVE-2026-98621",
  "modified": "2026-10-20T02:30:33.858660336Z",
  "published": "2026-10-18T15:19:41.211Z",
  "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/1d664be4ca49d1696e85239236f4988dfc4653c3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1eeec0c51fd5598da44080ed96bbd9880021c28b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2566866fc30965d915d0b52b5c3323b362619f0e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/43efb1f997e976f386aa89716f55870cd2cff9ad"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4b9bc21b2396c396d88dd909caaf73d5be6ff593"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/97f907203321eee2cc9132d5c9eb47698fb41d35"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c20f755338ca234e523dfc943719f194dfc1f903"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98621.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98621"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "net: gue: reject invalid REMCSUM offsets"
}