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Fencer Vulns
high 7.8

CVE-2026-23010 json

ipv6: Fix use-after-free in inet6_addr_del().

published 2026-01-25 9 mo ago modified 2026-10-15 25 d ago also EUVD-2026-4626

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 9%
public exploits
0
none known

Summary

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

ipv6: Fix use-after-free in inet6_addr_del().

syzbot reported use-after-free of inet6_ifaddr in inet6_addr_del(). [0]

The cited commit accidentally moved ipv6_del_addr() for mngtmpaddr before reading its ifp->flags for temporary addresses in inet6_addr_del().

Let's move ipv6_del_addr() down to fix the UAF.

[0]: BUG: KASAN: slab-use-after-free in inet6_addr_del.constprop.0+0x67a/0x6b0 net/ipv6/addrconf.c:3117 Read of size 4 at addr ffff88807b89c86c by task syz.3.1618/9593

CPU: 0 UID: 0 PID: 9593 Comm: syz.3.1618 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 inet6_addr_del.constprop.0+0x67a/0x6b0 net/ipv6/addrconf.c:3117 addrconf_del_ifaddr+0x11e/0x190 net/ipv6/addrconf.c:3181 inet6_ioctl+0x1e5/0x2b0 net/ipv6/af_inet6.c:582 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f164cf8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f164de64038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f164d1e5fa0 RCX: 00007f164cf8f749 RDX: 0000200000000000 RSI: 0000000000008936 RDI: 0000000000000003 RBP: 00007f164d013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f164d1e6038 R14: 00007f164d1e5fa0 R15: 00007ffde15c8288 </TASK>

Allocated by task 9593: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ipv6_add_addr+0x4e3/0x2010 net/ipv6/addrconf.c:1120 inet6_addr_add+0x256/0x9b0 net/ipv6/addrconf.c:3050 addrconf_add_ifaddr+0x1fc/0x450 net/ipv6/addrconf.c:3160 inet6_ioctl+0x103/0x2b0 net/ipv6/af_inet6.c:580 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6099: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free_freelist_hook mm/slub.c:2569 [inline] slab_free_bulk mm/slub.c:6696 [inline] kmem_cache_free_bulk mm/slub.c:7383 [inline] kmem_cache_free_bulk+0x2bf/0x680 mm/slub.c:7362 kfree_bulk include/linux/slab.h:830 [inline] kvfree_rcu_bulk+0x1b7/0x1e0 mm/slab_common.c:1523 kvfree_rcu_drain_ready mm/slab_common.c:1728 [inline] kfree_rcu_monitor+0x1d0/0x2f0 mm/slab_common.c:1801 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqu ---truncated---

Patch / fix

  • Linux Linux 6.1.162, 6.6.122, 6.12, 6.12.67, 6.18.7, 6.19
  • linux Debian 12 6.1.162-1
  • linux Debian 13 6.12.69-1
  • linux Debian 14 6.18.8-1

debian advisories DEBIAN-CVE-2026-23010

  • linux Ubuntu 24.04 LTS 6.8.0-117.117
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1055.58
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1058.61
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1054.60
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1055.56
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1056.62
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1041.44
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1056.60

ubuntu advisories UBUNTU-CVE-2026-23010

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 6.12.0-124.45.1.el10_1
  • rv RHEL 10.1 6.12.0-124.45.1.el10_1
  • perf RHEL 10.1 6.12.0-124.45.1.el10_1
  • rtla RHEL 10.1 6.12.0-124.45.1.el10_1
  • libperf RHEL 10.1 6.12.0-124.45.1.el10_1
  • kernel-rt RHEL 10.1 6.12.0-124.45.1.el10_1
  • kernel-64k RHEL 10.1 6.12.0-124.45.1.el10_1
  • kernel-core RHEL 10.1 6.12.0-124.45.1.el10_1

red hat advisories RHSA-2026:4723

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.34.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.34.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.34.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.34.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.34.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.34.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.34.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.34.1.150700.17.23.1

suse advisories SUSE-SU-2026:1081-1SUSE-SU-2026:20873-1SUSE-SU-2026:20838-1SUSE-SU-2026:20931-1SUSE-SU-2026:20845-1SUSE-SU-2026:20876-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.27.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.27.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.27.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.27.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.27.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.27.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.27.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.27.1

opensuse advisories openSUSE-SU-2026:20416-1

  • kernel-abi-stablelists AlmaLinux 10 6.12.0-124.45.1.el10_1

almalinux advisories ALSA-2026:4723

  • kernel Rocky Linux 10 6.12.0-124.45.1.el10_1

rocky linux advisories RLSA-2026:4723

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-2026-23010 updated cvss 7.3

kernel: Linux kernel: Use-after-free in IPv6 address deletion may lead to a denial of service

  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-124.45.1.el10_1, perf 6.12.0-124.45.1.el10_1, rtla 6.12.0-124.45.1.el10_1, python3-perf 6.12.0-124.45.1.el10_1, kernel-devel-matched 6.12.0-124.45.1.el10_1, kernel-64k-devel-matched 6.12.0-124.45.1.el10_1, +7 more Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-124.45.1.el10_1, kernel-64k 6.12.0-124.45.1.el10_1, kernel-core 6.12.0-124.45.1.el10_1, kernel-tools 6.12.0-124.45.1.el10_1, kernel-modules 6.12.0-124.45.1.el10_1, kernel-64k-core 6.12.0-124.45.1.el10_1, +28 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-124.45.1.el10_1, kernel-debuginfo-common-s390x 6.12.0-124.45.1.el10_1, kernel-debuginfo-common-x86_64 6.12.0-124.45.1.el10_1, kernel-debuginfo-common-aarch64 6.12.0-124.45.1.el10_1, kernel-debuginfo-common-ppc64le 6.12.0-124.45.1.el10_1 Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-124.45.1.el10_1, kernel-rt-64k 6.12.0-124.45.1.el10_1, kernel-rt-core 6.12.0-124.45.1.el10_1, kernel-rt-modules 6.12.0-124.45.1.el10_1, kernel-rt-64k-core 6.12.0-124.45.1.el10_1, kernel-rt-debug-core 6.12.0-124.45.1.el10_1, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-124.45.1.el10_1, kernel-rt-core 6.12.0-124.45.1.el10_1, kernel-rt-modules 6.12.0-124.45.1.el10_1, kernel-rt-debug-core 6.12.0-124.45.1.el10_1, kernel-rt-modules-core 6.12.0-124.45.1.el10_1, kernel-rt-debug-modules 6.12.0-124.45.1.el10_1, +4 more
    fixed: vendor fix RHSA-2026:4723
  • 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 Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 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-26-295-11 updated cvss 7.8

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-26-209-04 updated cvss 7.8

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

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.6 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

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% 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
NVD 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 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

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.