{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1"
            },
            {
              "fixed": "ec5f3005586a785689fd568361b0c5925cb1548b"
            },
            {
              "fixed": "19d114b93c94bdef70496f26685c2a6b242f41b3"
            },
            {
              "fixed": "594a064d603202b9ee21e07679d854e5c1750cc4"
            },
            {
              "fixed": "31f26a95eeee926946809ac456c61a3217936a62"
            },
            {
              "fixed": "e71f8e9ed6f311410b14741f6012afe01869c0fa"
            },
            {
              "fixed": "6d3724e616faf952c3adcf8414fc21a828ef3709"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.14.0"
            },
            {
              "fixed": "6.1.184"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.153"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.105"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.46"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74739.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_u32: skip hash tables in u32_bind_class()\n\nu32_walk() enumerates both struct tc_u_hnode and struct tc_u_knode\nthrough the walker callback. u32_bind_class() unconditionally casts the\npassed fh to tc_u_knode and accesses \u0026n-\u003eres, so when fh is actually a\ntc_u_hnode, which has no tcf_result member, this results in a\nslab-out-of-bounds read of res-\u003eclassid in tc_cls_bind_class().\n\nThe issue can be reproduced with the following commands:\n\n    tc qdisc add dev lo root handle 1: hfsc\n    tc class add dev lo parent 1: classid 1:1 hfsc sc rate 1000kbit\n    tc filter add dev lo parent 1:1 protocol ip prio 1 u32 match u32 0 0 flowid 1:1\n    tc class add dev lo parent 1: classid 1:2 hfsc sc rate 2000kbit\n\nFix this by skipping hash tables via the TC_U32_KEY(handle) check.",
  "id": "CVE-2026-74739",
  "modified": "2026-08-28T03:30:42.205923047Z",
  "published": "2026-08-26T14:36:51.746Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/19d114b93c94bdef70496f26685c2a6b242f41b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/31f26a95eeee926946809ac456c61a3217936a62"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/594a064d603202b9ee21e07679d854e5c1750cc4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6d3724e616faf952c3adcf8414fc21a828ef3709"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e71f8e9ed6f311410b14741f6012afe01869c0fa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec5f3005586a785689fd568361b0c5925cb1548b"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74739.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74739"
    },
    {
      "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": "net/sched: cls_u32: skip hash tables in u32_bind_class()"
}