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CVE-2026-23003

Updated on 25 Jan 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE ID
Links
NISTCIRCLRHELUbuntu

Overview

About vulnerability

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

ip6_tunnel: use skb_vlan_inet_prepare() in __ip6_tnl_rcv()

Blamed commit did not take care of VLAN encapsulations as spotted by syzbot [1].

Use skb_vlan_inet_prepare() instead of pskb_inet_may_pull().

[1] BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321 __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321 ip6ip6_dscp_ecn_decapsulate+0x16f/0x1b0 net/ipv6/ip6_tunnel.c:729 __ip6_tnl_rcv+0xed9/0x1b50 net/ipv6/ip6_tunnel.c:860 ip6_tnl_rcv+0xc3/0x100 net/ipv6/ip6_tunnel.c:903 gre_rcv+0x1529/0x1b90 net/ipv6/ip6_gre.c:-1 ip6_protocol_deliver_rcu+0x1c89/0x2c60 net/ipv6/ip6_input.c:438 ip6_input_finish+0x1f4/0x4a0 net/ipv6/ip6_input.c:489 NF_HOOK include/linux/netfilter.h:318 [inline] ip6_input+0x9c/0x330 net/ipv6/ip6_input.c:500 ip6_mc_input+0x7ca/0xc10 net/ipv6/ip6_input.c:590 dst_input include/net/dst.h:474 [inline] ip6_rcv_finish+0x958/0x990 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:318 [inline] ipv6_rcv+0xf1/0x3c0 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core net/core/dev.c:6139 [inline] __netif_receive_skb+0x1df/0xac0 net/core/dev.c:6252 netif_receive_skb_internal net/core/dev.c:6338 [inline] netif_receive_skb+0x57/0x630 net/core/dev.c:6397 tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485 tun_get_user+0x5c0e/0x6c60 drivers/net/tun.c:1953 tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0xbe2/0x15d0 fs/read_write.c:686 ksys_write fs/read_write.c:738 [inline] __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746 x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at: slab_post_alloc_hook mm/slub.c:4960 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x9e7/0x17a0 mm/slub.c:5315 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:586 __alloc_skb+0x805/0x1040 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc5/0xa60 net/core/skbuff.c:6712 sock_alloc_send_pskb+0xacc/0xc60 net/core/sock.c:2995 tun_alloc_skb drivers/net/tun.c:1461 [inline] tun_get_user+0x1142/0x6c60 drivers/net/tun.c:1794 tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0xbe2/0x15d0 fs/read_write.c:686 ksys_write fs/read_write.c:738 [inline] __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746 x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 6465 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025

Details

Affected product:
AlmaLinux 9.2 ESU , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
Affected packages:
linux @ 5.4.0 (+2 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
AlmaLinux 9.6 ESU Planned —
Amazon Linux 2023 Released
46 kernels
  • 6.1.79-99.164.amzn2023
  • 6.1.84-99.169.amzn2023
  • 6.1.82-99.168.amzn2023
  • 6.1.90-99.173.amzn2023
  • 6.1.87-99.174.amzn2023
  • 6.1.91-99.172.amzn2023
  • 6.1.97-104.177.amzn2023
  • 6.1.94-99.176.amzn2023
  • 6.1.102-108.177.amzn2023
  • 6.1.106-116.188.amzn2023
  • 6.1.102-111.182.amzn2023
  • 6.1.79-99.167.amzn2023
  • 6.1.92-99.174.amzn2023
  • 6.1.96-102.177.amzn2023
  • 6.1.109-118.189.amzn2023
  • 6.1.112-122.189.amzn2023
  • 6.1.111-120.187.amzn2023
  • 6.1.115-126.197.amzn2023
  • 6.1.119-129.201.amzn2023
  • 6.1.124-134.200.amzn2023
  • 6.1.127-135.201.amzn2023
  • 6.1.128-136.201.amzn2023
  • 6.1.129-138.220.amzn2023
  • 6.1.130-139.222.amzn2023
  • 6.1.131-143.221.amzn2023
  • 6.1.132-147.221.amzn2023
  • 6.1.134-150.224.amzn2023
  • 6.1.112-124.190.amzn2023
  • 6.1.140-154.222.amzn2023
  • 6.1.141-155.222.amzn2023
  • 6.1.134-152.225.amzn2023
  • 6.1.144-170.251.amzn2023
  • 6.1.147-172.266.amzn2023
  • 6.1.148-173.267.amzn2023
  • 6.1.150-174.273.amzn2023
  • 6.1.141-165.249.amzn2023
  • 6.1.141-167.250.amzn2023
  • 6.1.147-172.259.amzn2023
  • 6.1.153-175.280.amzn2023
  • 6.1.155-176.282.amzn2023
  • 6.1.156-177.286.amzn2023
  • 6.1.158-178.288.amzn2023
  • 6.1.159-181.297.amzn2023
  • 6.1.158-180.294.amzn2023
  • 6.1.159-182.297.amzn2023
  • 6.1.161-183.298.amzn2023
Debian 11 Released
9 kernels
  • 5.10.216-1
  • 5.10.218-1
  • 5.10.221-1
  • 5.10.223-1
  • 5.10.226-1
  • 5.10.234-1
  • 5.10.237-1
  • 5.10.244-1
  • 5.10.247-1
Debian 11 cloud Released
9 kernels
  • 5.10.216-1
  • 5.10.218-1
  • 5.10.221-1
  • 5.10.223-1
  • 5.10.226-1
  • 5.10.234-1
  • 5.10.237-1
  • 5.10.244-1
  • 5.10.247-1
Debian 12 Planned —
Debian 13 Planned —
Oracle Linux 8 UEK 7 Released
56 kernels
  • 5.15.0-205.149.5.1.el8uek
  • 5.15.0-205.149.5.4.el8uek
  • 5.15.0-206.153.7.el8uek
  • 5.15.0-206.153.7.1.el8uek
  • 5.15.0-207.156.6.el8uek
  • 5.15.0-208.159.3.el8uek
  • 5.15.0-208.159.3.2.el8uek
  • 5.15.0-209.161.7.el8uek
  • 5.15.0-209.161.7.1.el8uek
  • 5.15.0-209.161.7.2.el8uek
  • 5.15.0-210.163.7.el8uek
  • 5.15.0-300.163.18.el8uek
  • 5.15.0-300.163.18.1.el8uek
  • 5.15.0-300.163.18.1.1.el8uek
  • 5.15.0-301.163.5.2.el8uek
  • 5.15.0-302.167.6.el8uek
  • 5.15.0-300.163.18.7.el8uek
  • 5.15.0-302.167.6.1.el8uek
  • 5.15.0-303.171.5.2.el8uek
  • 5.15.0-303.171.5.2.1.el8uek
  • 5.15.0-304.171.4.el8uek
  • 5.15.0-304.171.4.1.el8uek
  • 5.15.0-304.171.4.3.el8uek
  • 5.15.0-303.171.5.2.2.el8uek
  • 5.15.0-305.176.4.el8uek
  • 5.15.0-306.177.4.el8uek
  • 5.15.0-306.177.4.1.el8uek
  • 5.15.0-307.178.5.el8uek
  • 5.15.0-308.179.6.el8uek
  • 5.15.0-308.179.6.2.el8uek
  • 5.15.0-308.179.6.3.el8uek
  • 5.15.0-309.180.4.el8uek
  • 5.15.0-308.179.6.7.el8uek
  • 5.15.0-309.180.4.2.el8uek
  • 5.15.0-308.179.6.11.el8uek
  • 5.15.0-310.184.5.2.el8uek
  • 5.15.0-310.184.5.3.el8uek
  • 5.15.0-311.185.9.el8uek
  • 5.15.0-308.179.6.14.el8uek
  • 5.15.0-312.187.5.el8uek
  • 5.15.0-312.187.5.1.el8uek
  • 5.15.0-312.187.5.2.el8uek
  • 5.15.0-312.187.5.3.el8uek
  • 5.15.0-308.179.6.16.el8uek
  • 5.15.0-313.189.5.1.el8uek
  • 5.15.0-313.189.5.2.el8uek
  • 5.15.0-313.189.5.3.el8uek
  • 5.15.0-314.193.5.3.el8uek
  • 5.15.0-314.193.5.4.el8uek
  • 5.15.0-314.193.5.5.el8uek
  • 5.15.0-315.196.5.1.el8uek
  • 5.15.0-315.196.5.2.el8uek
  • 5.15.0-316.196.4.1.el8uek
  • 5.15.0-316.196.4.2.el8uek
  • 5.15.0-317.197.5.1.el8uek
  • 5.15.0-317.197.5.2.el8uek
Oracle Linux 9 UEK 7 Released
56 kernels
  • 5.15.0-205.149.5.1.el9uek
  • 5.15.0-205.149.5.4.el9uek
  • 5.15.0-206.153.7.el9uek
  • 5.15.0-206.153.7.1.el9uek
  • 5.15.0-207.156.6.el9uek
  • 5.15.0-208.159.3.el9uek
  • 5.15.0-208.159.3.2.el9uek
  • 5.15.0-209.161.7.el9uek
  • 5.15.0-209.161.7.1.el9uek
  • 5.15.0-209.161.7.2.el9uek
  • 5.15.0-210.163.7.el9uek
  • 5.15.0-300.163.18.el9uek
  • 5.15.0-300.163.18.1.el9uek
  • 5.15.0-300.163.18.1.1.el9uek
  • 5.15.0-301.163.5.2.el9uek
  • 5.15.0-302.167.6.el9uek
  • 5.15.0-300.163.18.7.el9uek
  • 5.15.0-302.167.6.1.el9uek
  • 5.15.0-303.171.5.2.el9uek
  • 5.15.0-303.171.5.2.1.el9uek
  • 5.15.0-304.171.4.el9uek
  • 5.15.0-304.171.4.1.el9uek
  • 5.15.0-304.171.4.3.el9uek
  • 5.15.0-303.171.5.2.2.el9uek
  • 5.15.0-305.176.4.el9uek
  • 5.15.0-306.177.4.el9uek
  • 5.15.0-306.177.4.1.el9uek
  • 5.15.0-307.178.5.el9uek
  • 5.15.0-308.179.6.el9uek
  • 5.15.0-308.179.6.2.el9uek
  • 5.15.0-308.179.6.3.el9uek
  • 5.15.0-309.180.4.el9uek
  • 5.15.0-308.179.6.7.el9uek
  • 5.15.0-309.180.4.2.el9uek
  • 5.15.0-308.179.6.11.el9uek
  • 5.15.0-310.184.5.2.el9uek
  • 5.15.0-310.184.5.3.el9uek
  • 5.15.0-311.185.9.el9uek
  • 5.15.0-308.179.6.14.el9uek
  • 5.15.0-312.187.5.el9uek
  • 5.15.0-312.187.5.1.el9uek
  • 5.15.0-312.187.5.2.el9uek
  • 5.15.0-312.187.5.3.el9uek
  • 5.15.0-308.179.6.16.el9uek
  • 5.15.0-313.189.5.1.el9uek
  • 5.15.0-313.189.5.2.el9uek
  • 5.15.0-313.189.5.3.el9uek
  • 5.15.0-314.193.5.3.el9uek
  • 5.15.0-314.193.5.4.el9uek
  • 5.15.0-314.193.5.5.el9uek
  • 5.15.0-315.196.5.1.el9uek
  • 5.15.0-315.196.5.2.el9uek
  • 5.15.0-316.196.4.1.el9uek
  • 5.15.0-316.196.4.2.el9uek
  • 5.15.0-317.197.5.1.el9uek
  • 5.15.0-317.197.5.2.el9uek
Proxmox VE 7 5.15 Released
4 kernels
  • 5.15.149-1-pve-5.15.149-1
  • 5.15.152-1-pve-5.15.152-1
  • 5.15.158-1-pve_5.15.158-1
  • 5.15.158-2-pve_5.15.158-2
Ubuntu 20.04 HWE AWS Released
20 kernels
  • 5.15.0-1061.67~20.04.1
  • 5.15.0-1062.68~20.04.1
  • 5.15.0-1063.69~20.04.1
  • 5.15.0-1064.70~20.04.1
  • 5.15.0-1065.71~20.04.1
  • 5.15.0-1066.72~20.04.1
  • 5.15.0-1067.73~20.04.1
  • 5.15.0-1068.74~20.04.1
  • 5.15.0-1069.75~20.04.1
  • 5.15.0-1070.76~20.04.1
  • 5.15.0-1071.77~20.04.1
  • 5.15.0-1072.78~20.04.1
  • 5.15.0-1073.79~20.04.1
  • 5.15.0-1075.82~20.04.1
  • 5.15.0-1077.84~20.04.1
  • 5.15.0-1080.87~20.04.1
  • 5.15.0-1081.88~20.04.1
  • 5.15.0-1082.89~20.04.1
  • 5.15.0-1083.90~20.04.1
  • 5.15.0-1084.91~20.04.1
Ubuntu 20.04 HWE Azure Released
19 kernels
  • 5.15.0-1063.72~20.04.1
  • 5.15.0-1064.73~20.04.1
  • 5.15.0-1067.76~20.04.1
  • 5.15.0-1068.77~20.04.1
  • 5.15.0-1065.74~20.04.1
  • 5.15.0-1070.79~20.04.1
  • 5.15.0-1071.80~20.04.1
  • 5.15.0-1072.81~20.04.1
  • 5.15.0-1073.82~20.04.1
  • 5.15.0-1074.83~20.04.1
  • 5.15.0-1075.84~20.04.1
  • 5.15.0-1078.87~20.04.1
  • 5.15.0-1079.88~20.04.1
  • 5.15.0-1081.90~20.04.1
  • 5.15.0-1082.91~20.04.1
  • 5.15.0-1086.95~20.04.1
  • 5.15.0-1087.96~20.04.1
  • 5.15.0-1088.97~20.04.1
  • 5.15.0-1089.98~20.04.1
Ubuntu 22.04 Released
42 kernels
  • 5.15.0-106.116
  • 5.15.0-107.117
  • 5.15.0-112.122
  • 5.15.0-113.123
  • 5.15.0-116.126
  • 5.15.0-117.127
  • 5.15.0-118.128
  • 5.15.0-119.129
  • 5.15.0-121.131
  • 5.15.0-122.132
  • 5.15.0-124.134
  • 5.15.0-125.135
  • 5.15.0-127.137
  • 5.15.0-130.140
  • 5.15.0-126.136
  • 5.15.0-131.141
  • 5.15.0-128.138
  • 5.15.0-133.144
  • 5.15.0-134.145
  • 5.15.0-135.146
  • 5.15.0-136.147
  • 5.15.0-138.148
  • 5.15.0-139.149
  • 5.15.0-140.150
  • 5.15.0-141.151
  • 5.15.0-142.152
  • 5.15.0-143.153
  • 5.15.0-144.157
  • 5.15.0-151.161
  • 5.15.0-152.162
  • 5.15.0-153.163
  • 5.15.0-156.166
  • 5.15.0-157.167
  • 5.15.0-160.170
  • 5.15.0-161.171
  • 5.15.0-163.173
  • 5.15.0-164.174
  • 5.15.0-168.178
  • 5.15.0-170.180
  • 5.15.0-171.181
  • 5.15.0-173.183
  • 5.15.0-174.184
Ubuntu 22.04 AWS Released
39 kernels
  • 5.15.0-1061.67
  • 5.15.0-1062.68
  • 5.15.0-1063.69
  • 5.15.0-1064.70
  • 5.15.0-1065.71
  • 5.15.0-1066.72
  • 5.15.0-1067.73
  • 5.15.0-1068.74
  • 5.15.0-1069.75
  • 5.15.0-1070.76
  • 5.15.0-1071.77
  • 5.15.0-1072.78
  • 5.15.0-1073.79
  • 5.15.0-1076.83
  • 5.15.0-1078.85
  • 5.15.0-1079.86
  • 5.15.0-1080.87
  • 5.15.0-1081.88
  • 5.15.0-1082.89
  • 5.15.0-1083.90
  • 5.15.0-1084.91
  • 5.15.0-1085.92
  • 5.15.0-1086.93
  • 5.15.0-1087.94
  • 5.15.0-1088.95
  • 5.15.0-1089.96
  • 5.15.0-1090.97
  • 5.15.0-1091.98
  • 5.15.0-1092.99
  • 5.15.0-1093.100
  • 5.15.0-1095.102
  • 5.15.0-1096.103
  • 5.15.0-1097.104
  • 5.15.0-1098.105
  • 5.15.0-1099.106
  • 5.15.0-1100.107
  • 5.15.0-1101.108
  • 5.15.0-1103.110
  • 5.15.0-1104.111
Ubuntu 22.04 Azure Released
33 kernels
  • 5.15.0-1063.72
  • 5.15.0-1064.73
  • 5.15.0-1066.75
  • 5.15.0-1067.76
  • 5.15.0-1068.77
  • 5.15.0-1070.79
  • 5.15.0-1071.80
  • 5.15.0-1072.81
  • 5.15.0-1073.82
  • 5.15.0-1074.83
  • 5.15.0-1075.84
  • 5.15.0-1078.87
  • 5.15.0-1079.88
  • 5.15.0-1081.90
  • 5.15.0-1082.91
  • 5.15.0-1084.93
  • 5.15.0-1086.95
  • 5.15.0-1087.96
  • 5.15.0-1088.97
  • 5.15.0-1089.98
  • 5.15.0-1090.99
  • 5.15.0-1091.100
  • 5.15.0-1092.101
  • 5.15.0-1094.103
  • 5.15.0-1095.104
  • 5.15.0-1096.105
  • 5.15.0-1097.106
  • 5.15.0-1098.107
  • 5.15.0-1101.110
  • 5.15.0-1102.111
  • 5.15.0-1099.108
  • 5.15.0-1103.112
  • 5.15.0-1109.118
Ubuntu 24.04 Released
43 kernels
  • 6.8.0-35.35
  • 6.8.0-38.38
  • 6.8.0-36.36
  • 6.8.0-39.39
  • 6.8.0-40.40
  • 6.8.0-41.41
  • 6.8.0-44.44
  • 6.8.0-45.45
  • 6.8.0-31.31
  • 6.8.0-47.47
  • 6.8.0-48.48
  • 6.8.0-49.49
  • 6.8.0-50.51
  • 6.8.0-51.52
  • 6.8.0-52.53
  • 6.8.0-54.56
  • 6.8.0-55.57
  • 6.8.0-53.55
  • 6.8.0-56.58
  • 6.8.0-57.59
  • 6.8.0-58.60
  • 6.8.0-59.61
  • 6.8.0-60.63
  • 6.8.0-62.65
  • 6.8.0-63.66
  • 6.8.0-64.67
  • 6.8.0-71.71
  • 6.8.0-78.78
  • 6.8.0-79.79
  • 6.8.0-84.84
  • 6.8.0-85.85
  • 6.8.0-83.83
  • 6.8.0-86.87
  • 6.8.0-87.88
  • 6.8.0-88.89
  • 6.8.0-90.91
  • 6.8.0-94.96
  • 6.8.0-100.100
  • 6.8.0-101.101
  • 6.8.0-106.106
  • 6.8.0-107.107
  • 6.8.0-110.110
  • 6.8.0-111.111
Ubuntu 24.04 AWS Planned —