Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc3 MPTCP subflow_state_change recursion

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k0.00+

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc3. The affected element is the function subflow_state_change of the component MPTCP. This manipulation causes recursion. This vulnerability is handled as CVE-2026-97524. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc3. It has been declared as critical. Affected by this vulnerability is the function subflow_state_change of the component MPTCP. The manipulation with an unknown input leads to a recursion vulnerability. The CWE definition for the vulnerability is CWE-674. The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mptcp: avoid unneeded actions on subflow reset Once in a blue moon, the mptcp receive path can recursively call mptcp_data_ready() via state change under unlucky error conditions, and then try to hold the data lock again. Break the recursion loop explicitly checking for the exceptional condition. Add a new flag instead of using an existing one like 'closing', to exit early in subflow_state_change(), and explicitly flush the RX queue at reset time. This avoids unneeded processing to check for available data -- calling get_mapping_status() and more on a dying subflow -- but also in error reporting and worker scheduling. Note that we must consume the currently peeked skb before invoking mptcp_dss_corruption to avoid consuming it again after the eventual reset has freed it.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-97524 since 09/24/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc4 eliminates this vulnerability. Applying the patch 4b7abdcb5ba832fafab679f0d998af39cbc99307/b2dbcc1ed48b5ac070a41db4a52aade6823c4df0/ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f/2b0f561f21b27c40c91ea4975268a06092bd7e9c is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Recursion
CWE: CWE-674 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

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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-rc4
Patch: 4b7abdcb5ba832fafab679f0d998af39cbc99307/b2dbcc1ed48b5ac070a41db4a52aade6823c4df0/ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f/2b0f561f21b27c40c91ea4975268a06092bd7e9c

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-2026-97524 (🔒)
GCVE (CVE): GCVE-0-2026-97524
GCVE (VulDB): GCVE-100-409921

Entryinfo

Created: 09/25/2026 12:50
Changes: 09/25/2026 12:50 (59)
Complete: 🔍
Cache ID: 216::103

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