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Fencer Vulns
high 7.8

CVE-2026-43074 json

eventpoll: defer struct eventpoll free to RCU grace period

published 2026-05-06 6 mo ago modified 2026-10-19 20 d ago also EUVD-2026-27558

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

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

eventpoll: defer struct eventpoll free to RCU grace period

In certain situations, ep_free() in eventpoll.c will kfree the epi->ep eventpoll struct while it still being used by another concurrent thread. Defer the kfree() to an RCU callback to prevent UAF.

Patch / fix

  • Linux Linux 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0
  • linux Debian 13 6.12.85-1
  • linux Debian 14 6.19.14-1

debian advisories DEBIAN-CVE-2026-43074

  • linux Ubuntu 22.04 LTS 5.15.0-186.196
  • linux Ubuntu 24.04 LTS 6.8.0-136.136
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1112.119
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1061.64
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1112.122
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1064.72
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1108.114
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1059.67

ubuntu advisories UBUNTU-CVE-2026-43074

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 enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • rv enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • perf enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • rtla enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • libperf enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • kernel-64k enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • kernel-core enterprise linux nvidia 10 6.12.0-259.26.el10nv
  • kernel-tools enterprise linux nvidia 10 6.12.0-259.26.el10nv

red hat advisories RHSA-2026:73187RHSA-2026:39371RHSA-2026:38902RHSA-2026:37729RHSA-2026:36645RHSA-2026:36541

  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1
  • kernel-obs-build Linux Micro Extras 6.2 6.12.0-160000.36.1
  • kernel-rt Linux Micro 6.2 6.12.0-160000.36.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.36.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.36.1.160000.2.17
  • kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.36.1

suse advisories SUSE-SU-2026:22742-1SUSE-SU-2026:22769-1SUSE-SU-2026:22835-1SUSE-SU-2026:22812-1SUSE-SU-2026:2800-1SUSE-SU-2026:2799-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.36.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.36.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.36.1

opensuse advisories openSUSE-SU-2026:21388-1

  • kernel AlmaLinux 10 6.12.0-211.31.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.31.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.31.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.31.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.31.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.31.1.el10_2

almalinux advisories ALSA-2026:36541ALSA-2026:36645

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-2026-43074 updated cvss 7.3

kernel: eventpoll: defer struct eventpoll free to RCU grace period

  • Red Hat NVIDIA for RHEL 10 rv 6.12.0-231.15.el10nv, rv 6.12.0-259.26.el10nv, perf 6.12.0-231.15.el10nv, perf 6.12.0-259.26.el10nv, rtla 6.12.0-231.15.el10nv, rtla 6.12.0-259.26.el10nv, +59 more
    fixed: vendor fix RHSA-2026:36186
  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.127.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.127.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.127.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.127.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.127.1.el9_6
    fixed: vendor fix RHSA-2026:38902
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.23.1.el9_8, perf 5.14.0-687.23.1.el9_8, rtla 5.14.0-687.23.1.el9_8, python3-perf 5.14.0-687.23.1.el9_8, kernel-devel-matched 5.14.0-687.23.1.el9_8, kernel-64k-devel-matched 5.14.0-687.23.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:36645
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.31.1.el10_2, perf 6.12.0-211.31.1.el10_2, rtla 6.12.0-211.31.1.el10_2, python3-perf 6.12.0-211.31.1.el10_2, kernel-devel-matched 6.12.0-211.31.1.el10_2, kernel-64k-devel-matched 6.12.0-211.31.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.137.1.el9_4, perf 5.14.0-427.137.1.el9_4, rtla 5.14.0-427.137.1.el9_4, kernel-devel-matched 5.14.0-427.137.1.el9_4, kernel-64k-devel-matched 5.14.0-427.137.1.el9_4, kernel-debug-devel-matched 5.14.0-427.137.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:37729
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) rv 6.12.0-55.88.1.el10_0, perf 6.12.0-55.88.1.el10_0, rtla 6.12.0-55.88.1.el10_0, python3-perf 6.12.0-55.88.1.el10_0, kernel-devel-matched 6.12.0-55.88.1.el10_0, kernel-64k-devel-matched 6.12.0-55.88.1.el10_0, +7 more
    fixed: vendor fix RHSA-2026:39371
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.127.1.el9_6, perf 5.14.0-570.127.1.el9_6, rtla 5.14.0-570.127.1.el9_6, python3-perf 5.14.0-570.127.1.el9_6, kernel-devel-matched 5.14.0-570.127.1.el9_6, kernel-64k-devel-matched 5.14.0-570.127.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:38902
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.23.1.el9_8, kernel-64k 5.14.0-687.23.1.el9_8, kernel-core 5.14.0-687.23.1.el9_8, kernel-tools 5.14.0-687.23.1.el9_8, kernel-modules 5.14.0-687.23.1.el9_8, kernel-64k-core 5.14.0-687.23.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:36645
show 18 more
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.31.1.el10_2, kernel-64k 6.12.0-211.31.1.el10_2, kernel-core 6.12.0-211.31.1.el10_2, kernel-tools 6.12.0-211.31.1.el10_2, kernel-modules 6.12.0-211.31.1.el10_2, kernel-64k-core 6.12.0-211.31.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.137.1.el9_4, kernel 5.14.0-427.137.1.el9_4, kernel-64k 5.14.0-427.137.1.el9_4, kernel-core 5.14.0-427.137.1.el9_4, kernel-tools 5.14.0-427.137.1.el9_4, python3-perf 5.14.0-427.137.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:37729
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel 6.12.0-55.88.1.el10_0, kernel-64k 6.12.0-55.88.1.el10_0, kernel-core 6.12.0-55.88.1.el10_0, kernel-tools 6.12.0-55.88.1.el10_0, kernel-modules 6.12.0-55.88.1.el10_0, kernel-64k-core 6.12.0-55.88.1.el10_0, +27 more
    fixed: vendor fix RHSA-2026:39371
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.127.1.el9_6, kernel-64k 5.14.0-570.127.1.el9_6, kernel-core 5.14.0-570.127.1.el9_6, kernel-tools 5.14.0-570.127.1.el9_6, kernel-modules 5.14.0-570.127.1.el9_6, kernel-64k-core 5.14.0-570.127.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:38902
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.23.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.23.1.el9_8
    fixed: vendor fix RHSA-2026:36645
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.31.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.31.1.el10_2
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libperf 6.12.0-55.88.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.88.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.88.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.88.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.88.1.el10_0
    fixed: vendor fix RHSA-2026:39371
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.23.1.el9_8, kernel-rt-64k 5.14.0-687.23.1.el9_8, kernel-rt-core 5.14.0-687.23.1.el9_8, kernel-rt-modules 5.14.0-687.23.1.el9_8, kernel-rt-64k-core 5.14.0-687.23.1.el9_8, kernel-rt-debug-core 5.14.0-687.23.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:36645
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.31.1.el10_2, kernel-rt-64k 6.12.0-211.31.1.el10_2, kernel-rt-core 6.12.0-211.31.1.el10_2, kernel-rt-modules 6.12.0-211.31.1.el10_2, kernel-rt-64k-core 6.12.0-211.31.1.el10_2, kernel-rt-debug-core 6.12.0-211.31.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.137.1.el9_4, kernel-rt-core 5.14.0-427.137.1.el9_4, kernel-rt-modules 5.14.0-427.137.1.el9_4, kernel-rt-debug-core 5.14.0-427.137.1.el9_4, kernel-rt-modules-core 5.14.0-427.137.1.el9_4, kernel-rt-debug-modules 5.14.0-427.137.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:37729
  • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt 6.12.0-55.88.1.el10_0, kernel-rt-64k 6.12.0-55.88.1.el10_0, kernel-rt-core 6.12.0-55.88.1.el10_0, kernel-rt-modules 6.12.0-55.88.1.el10_0, kernel-rt-64k-core 6.12.0-55.88.1.el10_0, kernel-rt-debug-core 6.12.0-55.88.1.el10_0, +14 more
    fixed: vendor fix RHSA-2026:39371
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.127.1.el9_6, kernel-rt-64k 5.14.0-570.127.1.el9_6, kernel-rt-core 5.14.0-570.127.1.el9_6, kernel-rt-modules 5.14.0-570.127.1.el9_6, kernel-rt-64k-core 5.14.0-570.127.1.el9_6, kernel-rt-debug-core 5.14.0-570.127.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:38902
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.23.1.el9_8, kernel-rt-core 5.14.0-687.23.1.el9_8, kernel-rt-modules 5.14.0-687.23.1.el9_8, kernel-rt-debug-core 5.14.0-687.23.1.el9_8, kernel-rt-modules-core 5.14.0-687.23.1.el9_8, kernel-rt-debug-modules 5.14.0-687.23.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:36645
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.31.1.el10_2, kernel-rt-core 6.12.0-211.31.1.el10_2, kernel-rt-modules 6.12.0-211.31.1.el10_2, kernel-rt-debug-core 6.12.0-211.31.1.el10_2, kernel-rt-modules-core 6.12.0-211.31.1.el10_2, kernel-rt-debug-modules 6.12.0-211.31.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:36541
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.137.1.el9_4, kernel-rt-kvm 5.14.0-427.137.1.el9_4, kernel-rt-core 5.14.0-427.137.1.el9_4, kernel-rt-modules 5.14.0-427.137.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.137.1.el9_4, kernel-rt-debug-core 5.14.0-427.137.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:37729
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt 6.12.0-55.88.1.el10_0, kernel-rt-kvm 6.12.0-55.88.1.el10_0, kernel-rt-core 6.12.0-55.88.1.el10_0, kernel-rt-modules 6.12.0-55.88.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.88.1.el10_0, kernel-rt-debug-core 6.12.0-55.88.1.el10_0, +6 more
    fixed: vendor fix RHSA-2026:39371
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.127.1.el9_6, kernel-rt-kvm 5.14.0-570.127.1.el9_6, kernel-rt-core 5.14.0-570.127.1.el9_6, kernel-rt-modules 5.14.0-570.127.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.127.1.el9_6, kernel-rt-debug-core 5.14.0-570.127.1.el9_6, +6 more
    fixed: vendor fix RHSA-2026:38902
  • 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 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    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 ICSA-26-295-16 updated cvss 7.8

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    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
total
Assessed
23 d ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Classification

Weakness
  • CWE-416 Use After Free
  • CWE-401 Missing Release of Memory after Effective Lifetime
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.