Linux Kernel up to 6.18.7 l2tp l2tp_tunnel_del_work race condition

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4.9$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.7. This affects the function l2tp_tunnel_del_work of the component l2tp. Performing a manipulation results in race condition. This vulnerability is known as CVE-2026-23120. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.18.7. This affects the function l2tp_tunnel_del_work of the component l2tp. The manipulation with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: l2tp: avoid one data-race in l2tp_tunnel_del_work() We should read sk->sk_socket only when dealing with kernel sockets. syzbot reported the following data-race: BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release write to 0xffff88811c182b20 of 8 bytes by task 5365 on cpu 0: sk_set_socket include/net/sock.h:2092 [inline] sock_orphan include/net/sock.h:2118 [inline] sk_common_release+0xae/0x230 net/core/sock.c:4003 udp_lib_close+0x15/0x20 include/net/udp.h:325 inet_release+0xce/0xf0 net/ipv4/af_inet.c:437 __sock_release net/socket.c:662 [inline] sock_close+0x6b/0x150 net/socket.c:1455 __fput+0x29b/0x650 fs/file_table.c:468 ____fput+0x1c/0x30 fs/file_table.c:496 task_work_run+0x131/0x1a0 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x1e1/0x2b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88811c182b20 of 8 bytes by task 827 on cpu 1: l2tp_tunnel_del_work+0x2f/0x1a0 net/l2tp/l2tp_core.c:1418 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340 worker_thread+0x582/0x770 kernel/workqueue.c:3421 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 value changed: 0xffff88811b818000 -> 0x0000000000000000

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-23120 since 01/13/2026. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 299174 (Linux Distros Unpatched Vulnerability : CVE-2026-23120), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68 or 6.18.8 eliminates this vulnerability. Applying the patch 1f63ca44b4f419a1663d94d1bb0b4e2beb73fdb4/36c40a80109f1771d59558050b1a71e13c60c759/eae074dab764ea181bbed5e88626889319177498/68e92085427c84e7679ddb53c0d68836d220b6e7/3d6d414b214ce31659bded2f8df50c93a3769474/32d417497b79efb403d75f4c185fe6fd9d64b94f/7a29f6bf60f2590fe5e9c4decb451e19afad2bcf is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (299174) and CERT Bund (WID-SEC-2026-0421). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • IBM QRadar SIEM

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 299174
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23120

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.249/5.15.199/6.1.162/6.6.122/6.12.68/6.18.8
Patch: 1f63ca44b4f419a1663d94d1bb0b4e2beb73fdb4/36c40a80109f1771d59558050b1a71e13c60c759/eae074dab764ea181bbed5e88626889319177498/68e92085427c84e7679ddb53c0d68836d220b6e7/3d6d414b214ce31659bded2f8df50c93a3769474/32d417497b79efb403d75f4c185fe6fd9d64b94f/7a29f6bf60f2590fe5e9c4decb451e19afad2bcf

Timelineinfo

01/13/2026 CVE reserved
02/14/2026 +32 days Advisory disclosed
02/14/2026 +0 days VulDB entry created
05/06/2026 +81 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23120 (🔒)
GCVE (CVE): GCVE-0-2026-23120
GCVE (VulDB): GCVE-100-346095
CERT Bund: WID-SEC-2026-0421 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 02/14/2026 19:08
Updated: 05/06/2026 08:08
Changes: 02/14/2026 19:08 (59), 02/16/2026 23:13 (2), 02/19/2026 06:32 (1), 03/19/2026 02:47 (11), 05/06/2026 08:08 (7)
Complete: 🔍
Cache ID: 216::103

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