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Fencer Vulns
high 8.8

CVE-2026-53275 json

ipv6: mcast: Fix use-after-free when processing MLD queries

published 2026-06-25 4 mo ago modified 2026-10-19 20 d ago also EUVD-2026-39226

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

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

ipv6: mcast: Fix use-after-free when processing MLD queries

When processing an MLD query, a pointer to the multicast group address is retrieved when initially parsing the packet. This pointer is later dereferenced without being reloaded despite the fact that the skb header might have been reallocated following the pskb_may_pull() calls, leading to a use-after-free [1].

Fix by copying the multicast group address when the packet is initially parsed.

[1] BUG: KASAN: slab-use-after-free in __mld_query_work (net/ipv6/mcast.c:1512) Read of size 8 at addr ffff8881154b8e90 by task kworker/4:1/118

Workqueue: mld mld_query_work Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120) print_address_description.constprop.0 (mm/kasan/report.c:378) print_report (mm/kasan/report.c:482) kasan_report (mm/kasan/report.c:595) __mld_query_work (net/ipv6/mcast.c:1512) mld_query_work (net/ipv6/mcast.c:1563) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) </TASK>

[...]

Freed by task 118: kasan_save_stack (mm/kasan/common.c:57) kasan_save_track (mm/kasan/common.c:78) kasan_save_free_info (mm/kasan/generic.c:584) __kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285) kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566) pskb_expand_head (net/core/skbuff.c:2335) __pskb_pull_tail (net/core/skbuff.c:2878 (discriminator 4)) __mld_query_work (net/ipv6/mcast.c:1495 (discriminator 1)) mld_query_work (net/ipv6/mcast.c:1563) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245)

Patch / fix

  • Linux Linux 5.10.269, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1
  • linux Debian 12 6.1.176-1
  • linux Debian 13 6.12.94-1
  • linux Debian 14 7.0.13-1

debian advisories DEBIAN-CVE-2026-53275

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-146.146
  • 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 6.8.0-1066.69
  • 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 6.8.0-1070.78

ubuntu advisories UBUNTU-CVE-2026-53275

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-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-source-rt Real Time Module 15 SP7 6.4.0-150700.7.72.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.78.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.78.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.78.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.78.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.78.1

suse advisories SUSE-SU-2026:3810-1SUSE-SU-2026:3790-1SUSE-SU-2026:23244-1SUSE-SU-2026:23241-1SUSE-SU-2026:23194-1SUSE-SU-2026:23193-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.37.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.37.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.37.1

opensuse advisories openSUSE-SU-2026:21555-1

  • 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

  • kernel Azure Linux 3.0 6.6.143.1-1

azure linux advisories AZL-90647

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-2026-53275 updated cvss 5.9

kernel: ipv6: mcast: Fix use-after-free when processing MLD queries

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, 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: workaround, 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 ICSA-26-295-11 updated cvss 8.8

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-26-295-16 updated cvss 8.8

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
24 d ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

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.