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Fencer Vulns
high 7.8

CVE-2026-43339 json

ipv6: prevent possible UaF in addrconf_permanent_addr()

published 2026-05-08 6 mo ago modified 2026-10-19 20 d ago also EUVD-2026-28623

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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

ipv6: prevent possible UaF in addrconf_permanent_addr()

The mentioned helper try to warn the user about an exceptional condition, but the message is delivered too late, accessing the ipv6 after its possible deletion.

Reorder the statement to avoid the possible UaF; while at it, place the warning outside the idev->lock as it needs no protection.

Patch / fix

  • Linux Linux 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12, 7.0
  • linux Debian 12 6.1.170-1
  • linux Debian 13 6.12.85-1
  • linux Debian 14 6.19.12-1

debian advisories DEBIAN-CVE-2026-43339

  • 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-2026-43339

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 8 4.18.0-553.164.1.el8_10
  • perf RHEL 8 4.18.0-553.164.1.el8_10
  • bpftool RHEL 8 4.18.0-553.164.1.el8_10
  • kernel-core RHEL 8 4.18.0-553.164.1.el8_10
  • kernel-tools RHEL 8 4.18.0-553.164.1.el8_10
  • python3-perf RHEL 8 4.18.0-553.164.1.el8_10
  • kernel-modules RHEL 8 4.18.0-553.164.1.el8_10
  • kernel-zfcpdump RHEL 8 4.18.0-553.164.1.el8_10

red hat advisories RHSA-2026:68531RHSA-2026:68532RHSA-2026:66180RHSA-2026:64775

  • 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-2026:2799-1SUSE-SU-2026:2722-1

  • 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 8 4.18.0-553.164.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.164.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.164.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.164.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.164.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.164.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.164.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.164.1.el8_10

almalinux advisories ALSA-2026:68531ALSA-2026:68532ALSA-2026:66180

  • kernel-rt Rocky Linux 8 4.18.0-553.164.1.rt7.505.el8_10
  • kernel Rocky Linux 8 4.18.0-553.164.1.el8_10
  • kernel Rocky Linux 9 5.14.0-687.46.1.el9_8
  • kernel Rocky Linux 10 6.12.0-211.52.1.el10_2

rocky linux advisories RLSA-2026:68532RLSA-2026:68531RLSA-2026:66180RLSA-2026:64775

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-2026-43339 updated cvss 7.0

kernel: ipv6: prevent possible UaF in addrconf_permanent_addr()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more 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: no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.46.1.el9_8, perf 5.14.0-687.46.1.el9_8, rtla 5.14.0-687.46.1.el9_8, python3-perf 5.14.0-687.46.1.el9_8, kernel-devel-matched 5.14.0-687.46.1.el9_8, kernel-64k-devel-matched 5.14.0-687.46.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.52.1.el10_2, perf 6.12.0-211.52.1.el10_2, rtla 6.12.0-211.52.1.el10_2, python3-perf 6.12.0-211.52.1.el10_2, kernel-devel-matched 6.12.0-211.52.1.el10_2, kernel-64k-devel-matched 6.12.0-211.52.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.164.1.el8_10, kernel 4.18.0-553.164.1.el8_10, bpftool 4.18.0-553.164.1.el8_10, kernel-core 4.18.0-553.164.1.el8_10, kernel-tools 4.18.0-553.164.1.el8_10, python3-perf 4.18.0-553.164.1.el8_10, +15 more
    fixed: vendor fix RHSA-2026:68531
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.46.1.el9_8, kernel-64k 5.14.0-687.46.1.el9_8, kernel-core 5.14.0-687.46.1.el9_8, kernel-tools 5.14.0-687.46.1.el9_8, kernel-modules 5.14.0-687.46.1.el9_8, kernel-64k-core 5.14.0-687.46.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.52.1.el10_2, kernel-64k 6.12.0-211.52.1.el10_2, kernel-core 6.12.0-211.52.1.el10_2, kernel-tools 6.12.0-211.52.1.el10_2, kernel-modules 6.12.0-211.52.1.el10_2, kernel-64k-core 6.12.0-211.52.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.46.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.46.1.el9_8
    fixed: vendor fix RHSA-2026:66180
show 8 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.52.1.el10_2
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.164.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.164.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.164.1.el8_10
    fixed: vendor fix RHSA-2026:68531
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-kvm 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-core 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-modules 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-debug-kvm 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-debug-core 4.18.0-553.164.1.rt7.505.el8_10, +4 more
    fixed: vendor fix RHSA-2026:68532
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.46.1.el9_8, kernel-rt-64k 5.14.0-687.46.1.el9_8, kernel-rt-core 5.14.0-687.46.1.el9_8, kernel-rt-modules 5.14.0-687.46.1.el9_8, kernel-rt-64k-core 5.14.0-687.46.1.el9_8, kernel-rt-debug-core 5.14.0-687.46.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.52.1.el10_2, kernel-rt-64k 6.12.0-211.52.1.el10_2, kernel-rt-core 6.12.0-211.52.1.el10_2, kernel-rt-modules 6.12.0-211.52.1.el10_2, kernel-rt-64k-core 6.12.0-211.52.1.el10_2, kernel-rt-debug-core 6.12.0-211.52.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.46.1.el9_8, kernel-rt-core 5.14.0-687.46.1.el9_8, kernel-rt-modules 5.14.0-687.46.1.el9_8, kernel-rt-debug-core 5.14.0-687.46.1.el9_8, kernel-rt-modules-core 5.14.0-687.46.1.el9_8, kernel-rt-debug-modules 5.14.0-687.46.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:66180
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.52.1.el10_2, kernel-rt-core 6.12.0-211.52.1.el10_2, kernel-rt-modules 6.12.0-211.52.1.el10_2, kernel-rt-debug-core 6.12.0-211.52.1.el10_2, kernel-rt-modules-core 6.12.0-211.52.1.el10_2, kernel-rt-debug-modules 6.12.0-211.52.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-core 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-modules 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-debug-core 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-debug-modules 4.18.0-553.164.1.rt7.505.el8_10, kernel-rt-modules-extra 4.18.0-553.164.1.rt7.505.el8_10, +2 more
    fixed: vendor fix RHSA-2026:68532

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
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% 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

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.