{
  "threat_severity" : "Moderate",
  "public_date" : "2026-08-10T11:58:41Z",
  "bugzilla" : {
    "description" : "kernel: Linux kernel: PPPoE memory corruption via stale pointer",
    "id" : "2513233",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2513233"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.3",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-825",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\npppoe: reload header pointer after dev_hard_header()\npppoe_sendmsg() saves a pointer to the PPPoE header before calling\ndev_hard_header(). Device header callbacks are allowed to reallocate the\nskb head, invalidating pointers into it.\nThis can happen when a send is blocked in copy_from_user() while the first\nnon-Ethernet port is added to an empty team device. The team's delegated\nGRE header callback then expands the skb head. PPPoE subsequently writes\nsix bytes through the stale pointer into the freed head.\nReload the PPPoE header through the skb's network-header offset after\ndevice header creation. pskb_expand_head() updates that offset when it\nrelocates the head.", "A flaw was found in the Linux kernel's PPPoE (Point-to-Point Protocol over Ethernet) implementation. This vulnerability occurs because a pointer to network packet data is not updated after memory is reallocated, leading to the use of an outdated memory address. An attacker with local access could potentially trigger this condition, causing memory corruption. This could result in a system crash (denial of service) or other unpredictable system behavior." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Will not fix",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux for NVIDIA 26",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/a:redhat:enterprise_linux_nvidia:"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-68121\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-68121\nhttps://lore.kernel.org/linux-cve-announce/2026081056-CVE-2026-68121-b20f@gregkh/T" ],
  "name" : "CVE-2026-68121",
  "mitigation" : {
    "value" : "If PPPoE functionality is not required, prevent the `pppoe` kernel module from loading to mitigate this vulnerability. This can be achieved by creating a modprobe configuration file. A system reboot is required for the changes to take effect.\n```bash\necho \"install pppoe /bin/true\" > /etc/modprobe.d/disable-pppoe.conf\n```",
    "lang" : "en:us"
  },
  "csaw" : false
}