{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3"
            },
            {
              "fixed": "769723124b7c3b2bfea4cf68ad292698b87c8d01"
            },
            {
              "fixed": "24de676da63c1122d2c13b0d546238b66d1b4e62"
            },
            {
              "fixed": "5af905aa8e91ff8d94572a1e089558f21dcf24ed"
            },
            {
              "fixed": "e46e6bc97fb1f339730ff1ba74267fbf48e7a422"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.9.0"
            },
            {
              "fixed": "6.12.92"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.34"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64132.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: refresh hdr pointer before ioam6_event()\n\nReported by Sashiko:\n\nIn ipv6_hop_ioam(), the hdr pointer is initialized to point into the\nskb's linear data buffer. Later, the code calls skb_ensure_writable(),\nwhich might reallocate the buffer:\n\n\tif (skb_ensure_writable(skb, optoff + 2 + hdr-\u003eopt_len))\n\t\tgoto drop;\n\n\t/* Trace pointer may have changed */\n\ttrace = (struct ioam6_trace_hdr *)(skb_network_header(skb)\n\t\t\t\t\t   + optoff + sizeof(*hdr));\n\n\tioam6_fill_trace_data(skb, ns, trace, true);\n\n\tioam6_event(IOAM6_EVENT_TRACE, dev_net(skb-\u003edev),\n\t\t    GFP_ATOMIC, (void *)trace, hdr-\u003eopt_len - 2);\n\nIf the skb is cloned or lacks sufficient linear headroom,\nskb_ensure_writable() will invoke pskb_expand_head(), which reallocates\nthe skb's data buffer and frees the old one, invalidating pointers to\nit. While the code recalculates the trace pointer immediately after the\ncall to skb_ensure_writable(), it fails to recalculate the hdr pointer.\n\nThis patch fixes the above by recalculating the hdr pointer before\npassing hdr-\u003eopt_len to ioam6_event(), so that we avoid any UaF.",
  "id": "CVE-2026-64132",
  "modified": "2026-07-22T05:29:38.342115165Z",
  "published": "2026-07-19T15:40:27.590Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/24de676da63c1122d2c13b0d546238b66d1b4e62"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5af905aa8e91ff8d94572a1e089558f21dcf24ed"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/769723124b7c3b2bfea4cf68ad292698b87c8d01"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e46e6bc97fb1f339730ff1ba74267fbf48e7a422"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64132.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64132"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ipv6: ioam: refresh hdr pointer before ioam6_event()"
}