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Fencer Vulns
medium 5.5

CVE-2025-40300 json

x86/vmscape: Add conditional IBPB mitigation

published 2025-09-11 13 mo ago modified 2026-10-19 20 d ago also EUVD-2025-28976

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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

x86/vmscape: Add conditional IBPB mitigation

VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit.

Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB.

This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace.

The intent is to integrate and optimize these cases post-embargo.

[ dhansen: elaborate on suboptimal IBPB solution ]

Patch / fix

  • Linux Linux 3.17, 4.5, 5.10.244, 5.15.193, 6.1.152, 6.6.106, 6.12.47, 6.16.7, 6.17
  • Siemens SIMATIC CN 4100 V5.0
  • linux Debian 12 6.1.153-1
  • linux Debian 13 6.12.48-1
  • linux Debian 14 6.16.7-1

debian advisories DEBIAN-CVE-2025-40300

  • linux Ubuntu 22.04 LTS 5.15.0-161.171
  • linux Ubuntu 24.04 LTS 6.8.0-87.88
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1096.103
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1042.44
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1096.105
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1043.46
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1092.98
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1039.44

ubuntu advisories UBUNTU-CVE-2025-40300

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 10.1 6.12.0-124.9.1.el10_1
  • rv RHEL 10.1 6.12.0-124.9.1.el10_1
  • perf RHEL 10.1 6.12.0-124.9.1.el10_1
  • rtla RHEL 10.1 6.12.0-124.9.1.el10_1
  • libperf RHEL 10.1 6.12.0-124.9.1.el10_1
  • kernel-rt RHEL 10.1 6.12.0-124.9.1.el10_1
  • kernel-64k RHEL 10.1 6.12.0-124.9.1.el10_1
  • kernel-core RHEL 10.1 6.12.0-124.9.1.el10_1

red hat advisories RHSA-2026:0271RHSA-2025:22124RHSA-2025:22095RHSA-2025:22087RHSA-2025:22072RHSA-2025:22066

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.194.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.194.1
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 5.14.21-150400.24.194.1.150400.24.98.3
  • kernel-rt SLE Micro 5.5 5.14.21-150500.13.121.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.121.1

suse advisories SUSE-SU-2026:0617-1SUSE-SU-2026:0496-1SUSE-SU-2026:0474-1SUSE-SU-2026:0411-1SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1

  • spectre-meltdown-checker openSUSE Tumbleweed 26.36.0602723-1.1
  • kernel-source-longterm openSUSE Tumbleweed 6.18.16-1.1
  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.6.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.6.1

opensuse advisories openSUSE-SU-2026:11242-1openSUSE-SU-2026:10301-1openSUSE-SU-2025:20081-1openSUSE-SU-2025:15553-1

  • kernel AlmaLinux 9 5.14.0-570.62.1.el9_6
  • rv AlmaLinux 9 5.14.0-570.62.1.el9_6
  • perf AlmaLinux 9 5.14.0-570.62.1.el9_6
  • rtla AlmaLinux 9 5.14.0-570.62.1.el9_6
  • libperf AlmaLinux 9 5.14.0-570.62.1.el9_6
  • kernel-rt AlmaLinux 9 5.14.0-570.62.1.el9_6
  • kernel-64k AlmaLinux 9 5.14.0-570.62.1.el9_6
  • kernel-core AlmaLinux 9 5.14.0-570.62.1.el9_6

almalinux advisories ALSA-2025:19930ALSA-2025:19931ALSA-2025:19932

  • kernel-rt Rocky Linux 8 4.18.0-553.83.1.rt7.424.el8_10
  • kernel Rocky Linux 8 4.18.0-553.83.1.el8_10

rocky linux advisories RLSA-2025:19932RLSA-2025:19931

  • kernel Azure Linux 3.0 6.6.112.1-1
  • kernel CBL-Mariner 2.0 5.15.200.1-1

azure linux advisories AZL-67238AZL-74763

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-2025-40300 updated cvss 6.5

kernel: x86/vmscape: Add conditional IBPB mitigation

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “To mitigate this issue IBPB each time the kernel returns to QEMU.”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: workaround, no fix available, no fix planned “To mitigate this issue IBPB each time the kernel returns to QEMU.”
  • 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 “To mitigate this issue IBPB each time the kernel returns to QEMU.”
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.100.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.100.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.100.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.100.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.100.1.el9_4
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21760
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-611.7.1.el9_7, rv 5.14.0-570.62.1.el9_6, perf 5.14.0-611.7.1.el9_7, rtla 5.14.0-611.7.1.el9_7, perf 5.14.0-570.62.1.el9_6, rtla 5.14.0-570.62.1.el9_6, +20 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19930
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-124.9.1.el10_1, perf 6.12.0-124.9.1.el10_1, rtla 6.12.0-124.9.1.el10_1, python3-perf 6.12.0-124.9.1.el10_1, kernel-devel-matched 6.12.0-124.9.1.el10_1, kernel-64k-devel-matched 6.12.0-124.9.1.el10_1, +7 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21118
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) perf 5.14.0-70.155.1.el9_0, kernel-devel-matched 5.14.0-70.155.1.el9_0, kernel-debug-devel-matched 5.14.0-70.155.1.el9_0, kernel-debuginfo-common-s390x 5.14.0-70.155.1.el9_0, kernel-zfcpdump-devel-matched 5.14.0-70.155.1.el9_0, kernel-debuginfo-common-x86_64 5.14.0-70.155.1.el9_0, +2 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22066
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.148.1.el9_2, rtla 5.14.0-284.148.1.el9_2, kernel-devel-matched 5.14.0-284.148.1.el9_2, kernel-64k-devel-matched 5.14.0-284.148.1.el9_2, kernel-debug-devel-matched 5.14.0-284.148.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.148.1.el9_2, +5 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22095
show 31 more
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-devel-matched 6.12.0-55.52.1.el10_0, kernel-64k-devel-matched 6.12.0-55.52.1.el10_0, kernel-debug-devel-matched 6.12.0-55.52.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.52.1.el10_0, kernel-zfcpdump-devel-matched 6.12.0-55.52.1.el10_0, kernel-64k-debug-devel-matched 6.12.0-55.52.1.el10_0, +3 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2026:0271
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.100.1.el9_4, perf 5.14.0-427.100.1.el9_4, rtla 5.14.0-427.100.1.el9_4, kernel-devel-matched 5.14.0-427.100.1.el9_4, kernel-64k-devel-matched 5.14.0-427.100.1.el9_4, kernel-debug-devel-matched 5.14.0-427.100.1.el9_4, +6 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21760
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.83.1.el8_10, kernel 4.18.0-553.83.1.el8_10, bpftool 4.18.0-553.83.1.el8_10, kernel-core 4.18.0-553.83.1.el8_10, kernel-tools 4.18.0-553.83.1.el8_10, python3-perf 4.18.0-553.83.1.el8_10, +15 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19931
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-611.7.1.el9_7, kernel 5.14.0-570.62.1.el9_6, kernel-64k 5.14.0-611.7.1.el9_7, kernel-64k 5.14.0-570.62.1.el9_6, kernel-core 5.14.0-611.7.1.el9_7, kernel-core 5.14.0-570.62.1.el9_6, +60 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19930
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-124.9.1.el10_1, kernel-64k 6.12.0-124.9.1.el10_1, kernel-core 6.12.0-124.9.1.el10_1, kernel-tools 6.12.0-124.9.1.el10_1, kernel-modules 6.12.0-124.9.1.el10_1, kernel-64k-core 6.12.0-124.9.1.el10_1, +28 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21118
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) perf 4.18.0-372.170.1.el8_6, kernel 4.18.0-372.170.1.el8_6, bpftool 4.18.0-372.170.1.el8_6, kernel-core 4.18.0-372.170.1.el8_6, kernel-tools 4.18.0-372.170.1.el8_6, python3-perf 4.18.0-372.170.1.el8_6, +8 more Red Hat Enterprise Linux BaseOS E4S (v.8.6) perf 4.18.0-372.170.1.el8_6, kernel 4.18.0-372.170.1.el8_6, bpftool 4.18.0-372.170.1.el8_6, kernel-core 4.18.0-372.170.1.el8_6, kernel-tools 4.18.0-372.170.1.el8_6, python3-perf 4.18.0-372.170.1.el8_6, +15 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22006
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) perf 4.18.0-477.120.1.el8_8, kernel 4.18.0-477.120.1.el8_8, bpftool 4.18.0-477.120.1.el8_8, kernel-core 4.18.0-477.120.1.el8_8, kernel-tools 4.18.0-477.120.1.el8_8, python3-perf 4.18.0-477.120.1.el8_8, +9 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22072
  • Red Hat Enterprise Linux BaseOS E4S (v.9.0) kernel 5.14.0-70.155.1.el9_0, bpftool 5.14.0-70.155.1.el9_0, kernel-core 5.14.0-70.155.1.el9_0, kernel-tools 5.14.0-70.155.1.el9_0, python3-perf 5.14.0-70.155.1.el9_0, kernel-modules 5.14.0-70.155.1.el9_0, +14 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22066
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.148.1.el9_2, kernel 5.14.0-284.148.1.el9_2, kernel-64k 5.14.0-284.148.1.el9_2, kernel-core 5.14.0-284.148.1.el9_2, kernel-tools 5.14.0-284.148.1.el9_2, python3-perf 5.14.0-284.148.1.el9_2, +28 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22095
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel 6.12.0-55.52.1.el10_0, kernel-64k 6.12.0-55.52.1.el10_0, kernel-core 6.12.0-55.52.1.el10_0, kernel-tools 6.12.0-55.52.1.el10_0, kernel-modules 6.12.0-55.52.1.el10_0, kernel-64k-core 6.12.0-55.52.1.el10_0, +27 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2026:0271
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.100.1.el9_4, kernel 5.14.0-427.100.1.el9_4, kernel-64k 5.14.0-427.100.1.el9_4, kernel-core 5.14.0-427.100.1.el9_4, kernel-tools 5.14.0-427.100.1.el9_4, python3-perf 5.14.0-427.100.1.el9_4, +28 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21760
  • Red Hat Enterprise Linux BaseOS TUS (v.8.6) perf 4.18.0-372.170.1.el8_6, kernel 4.18.0-372.170.1.el8_6, bpftool 4.18.0-372.170.1.el8_6, kernel-core 4.18.0-372.170.1.el8_6, kernel-tools 4.18.0-372.170.1.el8_6, python3-perf 4.18.0-372.170.1.el8_6, +8 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22006
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) perf 4.18.0-477.120.1.el8_8, kernel 4.18.0-477.120.1.el8_8, bpftool 4.18.0-477.120.1.el8_8, kernel-core 4.18.0-477.120.1.el8_8, kernel-tools 4.18.0-477.120.1.el8_8, python3-perf 4.18.0-477.120.1.el8_8, +8 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22072
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-611.7.1.el9_7, libperf 5.14.0-570.62.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-611.7.1.el9_7, kernel-debuginfo-common-s390x 5.14.0-570.62.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-611.7.1.el9_7, kernel-debuginfo-common-aarch64 5.14.0-611.7.1.el9_7, +4 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19930
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-124.9.1.el10_1, kernel-debuginfo-common-s390x 6.12.0-124.9.1.el10_1, kernel-debuginfo-common-x86_64 6.12.0-124.9.1.el10_1, kernel-debuginfo-common-aarch64 6.12.0-124.9.1.el10_1, kernel-debuginfo-common-ppc64le 6.12.0-124.9.1.el10_1
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21118
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-debuginfo-common-s390x 6.12.0-55.52.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.52.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.52.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.52.1.el10_0
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2026:0271
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.83.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.83.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.83.1.el8_10
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19931
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-kvm 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-core 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-modules 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-debug-kvm 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-debug-core 4.18.0-553.83.1.rt7.424.el8_10, +4 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19932
  • Red Hat Enterprise Linux NFV E4S (v.9.0) kernel-rt 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-kvm 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-core 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-modules 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-debug-kvm 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-debug-core 5.14.0-70.155.1.rt21.227.el9_0, +4 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22087
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-611.7.1.el9_7, kernel-rt 5.14.0-570.62.1.el9_6, kernel-rt-64k 5.14.0-611.7.1.el9_7, kernel-rt-64k 5.14.0-570.62.1.el9_6, kernel-rt-core 5.14.0-611.7.1.el9_7, kernel-rt-core 5.14.0-570.62.1.el9_6, +34 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19930
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-124.9.1.el10_1, kernel-rt-64k 6.12.0-124.9.1.el10_1, kernel-rt-core 6.12.0-124.9.1.el10_1, kernel-rt-modules 6.12.0-124.9.1.el10_1, kernel-rt-64k-core 6.12.0-124.9.1.el10_1, kernel-rt-debug-core 6.12.0-124.9.1.el10_1, +14 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21118
  • Red Hat Enterprise Linux Real Time E4S (v.9.0) kernel-rt 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-core 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-modules 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-debug-core 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-debug-modules 5.14.0-70.155.1.rt21.227.el9_0, kernel-rt-modules-extra 5.14.0-70.155.1.rt21.227.el9_0, +2 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22087
  • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-core 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-modules 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-debug-core 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-modules-core 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-debug-modules 5.14.0-284.148.1.rt14.433.el9_2, +4 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22124
  • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt 6.12.0-55.52.1.el10_0, kernel-rt-64k 6.12.0-55.52.1.el10_0, kernel-rt-core 6.12.0-55.52.1.el10_0, kernel-rt-modules 6.12.0-55.52.1.el10_0, kernel-rt-64k-core 6.12.0-55.52.1.el10_0, kernel-rt-debug-core 6.12.0-55.52.1.el10_0, +14 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2026:0271
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.100.1.el9_4, kernel-rt-core 5.14.0-427.100.1.el9_4, kernel-rt-modules 5.14.0-427.100.1.el9_4, kernel-rt-debug-core 5.14.0-427.100.1.el9_4, kernel-rt-modules-core 5.14.0-427.100.1.el9_4, kernel-rt-debug-modules 5.14.0-427.100.1.el9_4, +4 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21760
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-611.7.1.el9_7, kernel-rt 5.14.0-570.62.1.el9_6, kernel-rt-core 5.14.0-611.7.1.el9_7, kernel-rt-kvm 5.14.0-570.62.1.el9_6, kernel-rt-core 5.14.0-570.62.1.el9_6, kernel-rt-modules 5.14.0-611.7.1.el9_7, +16 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19930
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-124.9.1.el10_1, kernel-rt-core 6.12.0-124.9.1.el10_1, kernel-rt-modules 6.12.0-124.9.1.el10_1, kernel-rt-debug-core 6.12.0-124.9.1.el10_1, kernel-rt-modules-core 6.12.0-124.9.1.el10_1, kernel-rt-debug-modules 6.12.0-124.9.1.el10_1, +4 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21118
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-kvm 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-core 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-modules 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-debug-kvm 5.14.0-284.148.1.rt14.433.el9_2, kernel-rt-debug-core 5.14.0-284.148.1.rt14.433.el9_2, +6 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:22124
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt 6.12.0-55.52.1.el10_0, kernel-rt-kvm 6.12.0-55.52.1.el10_0, kernel-rt-core 6.12.0-55.52.1.el10_0, kernel-rt-modules 6.12.0-55.52.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.52.1.el10_0, kernel-rt-debug-core 6.12.0-55.52.1.el10_0, +6 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2026:0271
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.100.1.el9_4, kernel-rt-kvm 5.14.0-427.100.1.el9_4, kernel-rt-core 5.14.0-427.100.1.el9_4, kernel-rt-modules 5.14.0-427.100.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.100.1.el9_4, kernel-rt-debug-core 5.14.0-427.100.1.el9_4, +6 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:21760
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-core 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-modules 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-debug-core 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-debug-modules 4.18.0-553.83.1.rt7.424.el8_10, kernel-rt-modules-extra 4.18.0-553.83.1.rt7.424.el8_10, +2 more
    fixed: vendor fix “To mitigate this issue IBPB each time the kernel returns to QEMU.” RHSA-2025:19932

5 more not affected in the full advisory

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 ICSA-26-295-11 updated cvss 6.5

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.7 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.7
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-26-209-04 updated cvss 6.5

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.6 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.6 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.6
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC CN 4100
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

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.