{
  "threat_severity" : "Important",
  "public_date" : "2026-07-25T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: Kernel: Remote out-of-bounds write in RDMA/siw",
    "id" : "2507089",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2507089"
  },
  "cvss3" : {
    "cvss3_base_score" : "8.8",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-787",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nRDMA/siw: bound Read Response placement to the RREAD length\nIn drivers/infiniband/sw/siw/siw_qp_rx.c, siw_proc_rresp() places each\ninbound Read Response DDP segment at sge->laddr + wqe->processed and then\naccumulates wqe->processed, but it never checks the running total against\nthe sink buffer length on continuation segments. siw_check_sge() resolves\nand validates the sink memory only on the first fragment (the if (!*mem)\nbranch), and siw_rresp_check_ntoh() compares the cumulative length against\nwqe->bytes only on the final segment (the !frx->more_ddp_segs guard).\nA connected siw peer that answers an outstanding RREAD with Read Response\nsegments that keep the DDP Last flag clear, carrying more total payload\nthan the RREAD requested, drives wqe->processed past the validated sink\nbuffer; the next siw_rx_data() call writes out of bounds at\nsge->laddr + wqe->processed. siw runs iWARP over ordinary routable TCP,\nso the peer is the remote end of an established RDMA connection and needs\nno local privilege.\nBound every segment before placement, exactly as siw_proc_send() and\nsiw_proc_write() already do for their tagged and untagged paths, and\nterminate the connection with a base-or-bounds DDP error when the\nRead Response would overrun the sink buffer.\nThis is the second receive-path length fix for this file. A separate\nchange rejects an MPA FPDU length that underflows the per-fragment\nremainder in the header decode; that guard does not cover this case,\nbecause here each individual segment length is self-consistent and only\nthe accumulated placement offset overruns the buffer.", "A flaw was found in the Linux kernel's Soft iWARP (siw) driver. A remote attacker, by sending specially crafted Read Response segments that exceed the requested length, can trigger an out-of-bounds write. This vulnerability can lead to memory corruption, potentially causing a kernel crash or privilege escalation." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63013",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.159.1.rt7.500.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63014",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.159.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-09-04T00:00:00Z",
    "advisory" : "RHSA-2026:63129",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.44.1.el9_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-09-04T00:00:00Z",
    "advisory" : "RHSA-2026:63129",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.44.1.el9_8"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-64268\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64268\nhttps://lore.kernel.org/linux-cve-announce/2026072559-CVE-2026-64268-629a@gregkh/T" ],
  "name" : "CVE-2026-64268",
  "mitigation" : {
    "value" : "To mitigate this issue, prevent the `siw` kernel module from loading. Create a file `/etc/modprobe.d/blacklist-siw.conf` with the following content:\n```\nblacklist siw\ninstall siw /bin/true\n```\nAfter creating the file, regenerate the initramfs and reboot the system for the changes to take effect:\n```bash\ndracut -f -v\nreboot\n```\nThis mitigation will disable the Soft iWARP functionality, which may impact applications relying on it. A system reboot is required for the changes to be fully applied.",
    "lang" : "en:us"
  },
  "csaw" : false
}