Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2 mptcp subflow_ulp_clone improper synchronization

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.5	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. This issue affects the function subflow_ulp_clone of the component mptcp. The manipulation results in improper synchronization. This vulnerability is known as CVE-2026-97568. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. Affected is the function subflow_ulp_clone of the component mptcp. The manipulation with an unknown input leads to a improper synchronization vulnerability. CWE is classifying the issue as CWE-662. The product utilizes multiple threads or processes to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mptcp: syncookies: remember the request backup flag Instead of using an uninitialised bit when copying the info in subflow_ulp_clone(). To fix this, no need to extend the join_entry structure: backup is coming from struct mptcp_subflow_request_sock, only one bit. Do the same here by using one bit for both.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-97568 since 09/24/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/25/2026).

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc3 eliminates this vulnerability. Applying the patch 61178d0b85b4b1b53e78b06e89d018d22d102f88/00b2bd518911e0daab00f4749cce68c191ccebb4/06d649f9cd03a9f8e768a658b20acf8d2c8022e0/b76c0e28b392620dfbaf92cdeedbf115820b44cb is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.110
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 6.18.51
• 6.18.52
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1
• 7.3-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Improper synchronization
CWE: CWE-662
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.111/6.18.53/7.2.7/7.3-rc3
Patch: 61178d0b85b4b1b53e78b06e89d018d22d102f88/00b2bd518911e0daab00f4749cce68c191ccebb4/06d649f9cd03a9f8e768a658b20acf8d2c8022e0/b76c0e28b392620dfbaf92cdeedbf115820b44cb

Timelineinfo

09/24/2026 CVE reserved
09/25/2026 +1 days Advisory disclosed
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-97568 (🔒)
GCVE (CVE): GCVE-0-2026-97568
GCVE (VulDB): GCVE-100-410040

Entryinfo

Created: 09/25/2026 14:04
Changes: 09/25/2026 14:04 (59)
Complete: 🔍
Cache ID: 216::103

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