{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "48eb03dd26304c24f03bdbb9382e89c8564e71df"
            },
            {
              "fixed": "0dfe05b938435892875e07771170051346412df9"
            },
            {
              "fixed": "bfdfd2706d5fb2cd496a1506e680daf979309c8b"
            },
            {
              "fixed": "22ba97ea9cc1f63a0d0244fae38057ed452b6ac7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.8.0"
            },
            {
              "fixed": "6.18.36"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53250.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()\n\nThe TX metadata area resides in the UMEM buffer which is memory-mapped\nand concurrently writable by userspace. In xsk_skb_metadata(),\ncsum_start and csum_offset are read from shared memory for bounds\nvalidation, then read again for skb assignment. A malicious userspace\napplication can race to overwrite these values between the two reads,\nbypassing the bounds check and causing out-of-bounds memory access\nduring checksum computation in the transmit path.\n\nFix this by reading csum_start and csum_offset into local variables\nonce, then using the local copies for both validation and assignment.\n\nNote that other metadata fields (flags, launch_time) and the cached\ncsum fields may be mutually inconsistent due to concurrent userspace\nwrites, but this is benign: the only security-critical invariant is\nthat each field's validated value is the same one used, which local\ncaching guarantees.",
  "id": "CVE-2026-53250",
  "modified": "2026-07-08T05:35:55.880867572Z",
  "published": "2026-06-25T08:39:42.630Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53250.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53250"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "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": "xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()"
}