{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "a5127501c8d30b5728791b1e340284ca5c9cc4bd"
            },
            {
              "fixed": "e6f4ffe8596947a595c9544e73a73adcb0568b88"
            },
            {
              "fixed": "ac6985903db047eaff54db929e4bf6b06782788e"
            },
            {
              "fixed": "c221ed63a2769a0af8bd849dfe25740048f34ef4"
            },
            {
              "fixed": "eda30846ea54f8ed218468e5480c8305ca645e37"
            },
            {
              "fixed": "b1dfd6b27df35ef4f87825aa5f607378d23ff0f2"
            },
            {
              "fixed": "e1af65c669ebb1666c54576614c01a7f9ffcfff6"
            },
            {
              "fixed": "71a98248c63c535eaa4d4c22f099b68d902006d0"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "5.10.258"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.209"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.169"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.135"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.82"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.23"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31664.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: clear trailing padding in build_polexpire()\n\nbuild_expire() clears the trailing padding bytes of struct\nxfrm_user_expire after setting the hard field via memset_after(),\nbut the analogous function build_polexpire() does not do this for\nstruct xfrm_user_polexpire.\n\nThe padding bytes after the __u8 hard field are left\nuninitialized from the heap allocation, and are then sent to\nuserspace via netlink multicast to XFRMNLGRP_EXPIRE listeners,\nleaking kernel heap memory contents.\n\nAdd the missing memset_after() call, matching build_expire().",
  "id": "CVE-2026-31664",
  "modified": "2026-07-08T05:39:09.812792425Z",
  "published": "2026-04-24T14:45:13.922Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/71a98248c63c535eaa4d4c22f099b68d902006d0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5127501c8d30b5728791b1e340284ca5c9cc4bd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ac6985903db047eaff54db929e4bf6b06782788e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b1dfd6b27df35ef4f87825aa5f607378d23ff0f2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c221ed63a2769a0af8bd849dfe25740048f34ef4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e1af65c669ebb1666c54576614c01a7f9ffcfff6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e6f4ffe8596947a595c9544e73a73adcb0568b88"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eda30846ea54f8ed218468e5480c8305ca645e37"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31664.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31664"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "xfrm: clear trailing padding in build_polexpire()"
}