Skip to content
Fencer Vulns
critical 9.8

CVE-2026-64268 in the critical feed json

RDMA/siw: bound Read Response placement to the RREAD length

published 2026-07-25 3 mo ago modified 2026-10-19 20 d ago also EUVD-2026-48980

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

RDMA/siw: bound Read Response placement to the RREAD length

In drivers/infiniband/sw/siw/siw_qp_rx.c, siw_proc_rresp() places each inbound Read Response DDP segment at sge->laddr + wqe->processed and then accumulates wqe->processed, but it never checks the running total against the sink buffer length on continuation segments. siw_check_sge() resolves and validates the sink memory only on the first fragment (the if (!*mem) branch), and siw_rresp_check_ntoh() compares the cumulative length against wqe->bytes only on the final segment (the !frx->more_ddp_segs guard).

A connected siw peer that answers an outstanding RREAD with Read Response segments that keep the DDP Last flag clear, carrying more total payload than the RREAD requested, drives wqe->processed past the validated sink buffer; the next siw_rx_data() call writes out of bounds at sge->laddr + wqe->processed. siw runs iWARP over ordinary routable TCP, so the peer is the remote end of an established RDMA connection and needs no local privilege.

Bound every segment before placement, exactly as siw_proc_send() and siw_proc_write() already do for their tagged and untagged paths, and terminate the connection with a base-or-bounds DDP error when the Read Response would overrun the sink buffer.

This is the second receive-path length fix for this file. A separate change rejects an MPA FPDU length that underflows the per-fragment remainder in the header decode; that guard does not cover this case, because here each individual segment length is self-consistent and only the accumulated placement offset overruns the buffer.

Patch / fix

  • Linux Linux 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2
  • linux Debian 12 6.1.180-1
  • linux Debian 13 6.12.96-1
  • linux Debian 14 7.1.4-1
  • linux-6.12 Debian 12 6.12.100-1~deb12u1

debian advisories DEBIAN-CVE-2026-64268

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-31.31
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1012.12
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-64268

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-687.44.1.el9_8
  • rv RHEL 9 5.14.0-687.44.1.el9_8
  • perf RHEL 9 5.14.0-687.44.1.el9_8
  • rtla RHEL 9 5.14.0-687.44.1.el9_8
  • libperf RHEL 9 5.14.0-687.44.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.44.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.44.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.44.1.el9_8

red hat advisories RHSA-2026:70482RHSA-2026:70483RHSA-2026:69906RHSA-2026:69837RHSA-2026:68100RHSA-2026:67720

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.189.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.189.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.189.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.189.1.150500.6.87.4
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1

suse advisories SUSE-SU-2026:4595-1SUSE-SU-2026:4254-1SUSE-SU-2026:4369-1SUSE-SU-2026:4347-1SUSE-SU-2026:4284-1SUSE-SU-2026:23887-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1openSUSE-SU-2026:11476-1

  • kernel-rt AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-core AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-modules AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-core AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-modules AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-modules-extra AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel-rt-debug-modules-extra AlmaLinux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel AlmaLinux 8 4.18.0-553.159.1.el8_10

almalinux advisories ALSA-2026:63013ALSA-2026:63014ALSA-2026:63129

  • kernel Rocky Linux 9 5.14.0-687.44.1.el9_8
  • kernel-rt Rocky Linux 8 4.18.0-553.159.1.rt7.500.el8_10
  • kernel Rocky Linux 8 4.18.0-553.159.1.el8_10

rocky linux advisories RLSA-2026:63129RLSA-2026:63013RLSA-2026:63014

  • kernel Azure Linux 3.0 6.6.145.2-1

azure linux advisories AZL-93798

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-64268 updated cvss 8.8

kernel: Kernel: Remote out-of-bounds write in RDMA/siw

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.141.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.141.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.141.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.141.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.141.1.el9_6
    fixed: vendor fix RHSA-2026:67720
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.44.1.el9_8, perf 5.14.0-687.44.1.el9_8, rtla 5.14.0-687.44.1.el9_8, python3-perf 5.14.0-687.44.1.el9_8, kernel-devel-matched 5.14.0-687.44.1.el9_8, kernel-64k-devel-matched 5.14.0-687.44.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.193.1.el9_2, rtla 5.14.0-284.193.1.el9_2, kernel-devel-matched 5.14.0-284.193.1.el9_2, kernel-64k-devel-matched 5.14.0-284.193.1.el9_2, kernel-debug-devel-matched 5.14.0-284.193.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.193.1.el9_2, +5 more
    fixed: vendor fix RHSA-2026:70482
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.150.1.el9_4, perf 5.14.0-427.150.1.el9_4, rtla 5.14.0-427.150.1.el9_4, kernel-devel-matched 5.14.0-427.150.1.el9_4, kernel-64k-devel-matched 5.14.0-427.150.1.el9_4, kernel-debug-devel-matched 5.14.0-427.150.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:68100
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.141.1.el9_6, perf 5.14.0-570.141.1.el9_6, rtla 5.14.0-570.141.1.el9_6, python3-perf 5.14.0-570.141.1.el9_6, kernel-devel-matched 5.14.0-570.141.1.el9_6, kernel-64k-devel-matched 5.14.0-570.141.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:67720
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.159.1.el8_10, kernel 4.18.0-553.159.1.el8_10, bpftool 4.18.0-553.159.1.el8_10, kernel-core 4.18.0-553.159.1.el8_10, kernel-tools 4.18.0-553.159.1.el8_10, python3-perf 4.18.0-553.159.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:63014
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.44.1.el9_8, kernel-64k 5.14.0-687.44.1.el9_8, kernel-core 5.14.0-687.44.1.el9_8, kernel-tools 5.14.0-687.44.1.el9_8, kernel-modules 5.14.0-687.44.1.el9_8, kernel-64k-core 5.14.0-687.44.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:63129
show 22 more
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) perf 4.18.0-305.206.1.el8_4, kernel 4.18.0-305.206.1.el8_4, bpftool 4.18.0-305.206.1.el8_4, kernel-core 4.18.0-305.206.1.el8_4, kernel-tools 4.18.0-305.206.1.el8_4, python3-perf 4.18.0-305.206.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:65710
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.216.1.el8_6, kernel 4.18.0-372.216.1.el8_6, bpftool 4.18.0-372.216.1.el8_6, kernel-core 4.18.0-372.216.1.el8_6, kernel-tools 4.18.0-372.216.1.el8_6, python3-perf 4.18.0-372.216.1.el8_6, +8 more
    fixed: vendor fix RHSA-2026:69906
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.168.1.el8_8, kernel 4.18.0-477.168.1.el8_8, bpftool 4.18.0-477.168.1.el8_8, kernel-core 4.18.0-477.168.1.el8_8, kernel-tools 4.18.0-477.168.1.el8_8, python3-perf 4.18.0-477.168.1.el8_8, +9 more
    fixed: vendor fix RHSA-2026:69837
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.193.1.el9_2, kernel 5.14.0-284.193.1.el9_2, kernel-64k 5.14.0-284.193.1.el9_2, kernel-core 5.14.0-284.193.1.el9_2, kernel-tools 5.14.0-284.193.1.el9_2, python3-perf 5.14.0-284.193.1.el9_2, +28 more
    fixed: vendor fix RHSA-2026:70482
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.150.1.el9_4, kernel 5.14.0-427.150.1.el9_4, kernel-64k 5.14.0-427.150.1.el9_4, kernel-core 5.14.0-427.150.1.el9_4, kernel-tools 5.14.0-427.150.1.el9_4, python3-perf 5.14.0-427.150.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:68100
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.141.1.el9_6, kernel-64k 5.14.0-570.141.1.el9_6, kernel-core 5.14.0-570.141.1.el9_6, kernel-tools 5.14.0-570.141.1.el9_6, kernel-modules 5.14.0-570.141.1.el9_6, kernel-64k-core 5.14.0-570.141.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:67720
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) perf 4.18.0-305.206.1.el8_4, kernel 4.18.0-305.206.1.el8_4, bpftool 4.18.0-305.206.1.el8_4, kernel-core 4.18.0-305.206.1.el8_4, kernel-tools 4.18.0-305.206.1.el8_4, python3-perf 4.18.0-305.206.1.el8_4, +8 more
    fixed: vendor fix RHSA-2026:65710
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) perf 4.18.0-372.216.1.el8_6, kernel 4.18.0-372.216.1.el8_6, bpftool 4.18.0-372.216.1.el8_6, kernel-core 4.18.0-372.216.1.el8_6, kernel-tools 4.18.0-372.216.1.el8_6, python3-perf 4.18.0-372.216.1.el8_6, +15 more
    fixed: vendor fix RHSA-2026:69906
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.168.1.el8_8, kernel 4.18.0-477.168.1.el8_8, bpftool 4.18.0-477.168.1.el8_8, kernel-core 4.18.0-477.168.1.el8_8, kernel-tools 4.18.0-477.168.1.el8_8, python3-perf 4.18.0-477.168.1.el8_8, +8 more
    fixed: vendor fix RHSA-2026:69837
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.44.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.44.1.el9_8
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.159.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.159.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.159.1.el8_10
    fixed: vendor fix RHSA-2026:63014
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-kvm 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-kvm 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-core 4.18.0-553.159.1.rt7.500.el8_10, +4 more
    fixed: vendor fix RHSA-2026:63013
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.44.1.el9_8, kernel-rt-64k 5.14.0-687.44.1.el9_8, kernel-rt-core 5.14.0-687.44.1.el9_8, kernel-rt-modules 5.14.0-687.44.1.el9_8, kernel-rt-64k-core 5.14.0-687.44.1.el9_8, kernel-rt-debug-core 5.14.0-687.44.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-core 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-modules 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-debug-core 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-modules-core 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-debug-modules 5.14.0-284.193.1.rt14.478.el9_2, +4 more
    fixed: vendor fix RHSA-2026:70483
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.150.1.el9_4, kernel-rt-core 5.14.0-427.150.1.el9_4, kernel-rt-modules 5.14.0-427.150.1.el9_4, kernel-rt-debug-core 5.14.0-427.150.1.el9_4, kernel-rt-modules-core 5.14.0-427.150.1.el9_4, kernel-rt-debug-modules 5.14.0-427.150.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:68100
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.141.1.el9_6, kernel-rt-64k 5.14.0-570.141.1.el9_6, kernel-rt-core 5.14.0-570.141.1.el9_6, kernel-rt-modules 5.14.0-570.141.1.el9_6, kernel-rt-64k-core 5.14.0-570.141.1.el9_6, kernel-rt-debug-core 5.14.0-570.141.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:67720
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.44.1.el9_8, kernel-rt-core 5.14.0-687.44.1.el9_8, kernel-rt-modules 5.14.0-687.44.1.el9_8, kernel-rt-debug-core 5.14.0-687.44.1.el9_8, kernel-rt-modules-core 5.14.0-687.44.1.el9_8, kernel-rt-debug-modules 5.14.0-687.44.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:63129
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-kvm 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-core 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-modules 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-debug-kvm 5.14.0-284.193.1.rt14.478.el9_2, kernel-rt-debug-core 5.14.0-284.193.1.rt14.478.el9_2, +6 more
    fixed: vendor fix RHSA-2026:70483
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.150.1.el9_4, kernel-rt-kvm 5.14.0-427.150.1.el9_4, kernel-rt-core 5.14.0-427.150.1.el9_4, kernel-rt-modules 5.14.0-427.150.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.150.1.el9_4, kernel-rt-debug-core 5.14.0-427.150.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:68100
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.141.1.el9_6, kernel-rt-kvm 5.14.0-570.141.1.el9_6, kernel-rt-core 5.14.0-570.141.1.el9_6, kernel-rt-modules 5.14.0-570.141.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.141.1.el9_6, kernel-rt-debug-core 5.14.0-570.141.1.el9_6, +6 more
    fixed: vendor fix RHSA-2026:67720
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-core 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-debug-modules 4.18.0-553.159.1.rt7.500.el8_10, kernel-rt-modules-extra 4.18.0-553.159.1.rt7.500.el8_10, +2 more
    fixed: vendor fix RHSA-2026:63013
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.