VulnerabilityPublished 25 Sep 2026Updated 19 Oct 2026

CVE-2026-97524: Linux kernel · mptcp: avoid unneeded actions on subflow reset

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f : patch Linux kernel soon.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f, b2dbcc1ed48b5ac070a41db4a52aade6823c4df0, a370e56024df0b07e3120c45a9773ae123819fd6 +10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=5.10.228 <5.10.271 >=5.15.169 <5.15.222 >=6.1.113 <6.1.189 >=6.6.57 <6.6.158 >=6.11.4 <6.12	Fixed in ce7e4ede01ed3e47a48c0f1ce1d87bf4864bee9f b2dbcc1ed48b5ac070a41db4a52aade6823c4df0 a370e56024df0b07e3120c45a9773ae123819fd6 1962841387087970d75ba8b8d4c2aa2d45705e50 83a7dcdd2b1060484528da70a643125174d47e5a 6d669c740933124eae3df8cfc15995af9bcc6aba 6.12 6.6.158 6.1.189 5.15.222 5.10.271 4b7abdcb5ba832fafab679f0d998af39cbc99307 2b0f561f21b27c40c91ea4975268a06092bd7e9c
LinuxLinux	Affected =6.12	Fixed in–

AI-suggested

A fix for this vulnerability is available and has been incorporated in Linux kernel versions 5.10.271, 5.15.222, 6.1.189, 6.6.158, and 6.12 and later. Users and administrators should upgrade affected Linux kernel versions to these fixed releases to mitigate the issue. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-97524 is a high-severity vulnerability in the Linux kernel's Multipath TCP (mptcp) implementation. It involves unneeded recursive actions on subflow reset that can cause excessive processing and potential denial of service. The issue arises when the mptcp receive path recursively calls mptcp_data_ready() under rare error conditions, leading to attempts to re-acquire a data lock. The fix introduces a new flag to break this recursion and explicitly flushes the RX queue during subflow reset, preventing unnecessary processing and avoiding double consumption of data buffers.

Impact

The vulnerability can lead to excessive processing in the kernel's mptcp receive path, potentially causing denial of service (DoS) conditions due to recursive locking and redundant operations on subflows that are resetting. The CVSS score of 7.5 with an impact vector indicating no confidentiality or integrity impact but high availability impact confirms this. There is no indication of remote code execution or data leakage. No known exploits in the wild have been reported.

Summary

This vulnerability in the Linux kernel's mptcp component occurs due to recursive calls in the receive path triggered by subflow reset events under rare error conditions. The recursion causes the system to attempt to hold the data lock multiple times and perform unnecessary processing such as get_mapping_status() on a subflow that is being reset. The patch adds a dedicated flag to exit early in subflow_state_change() and explicitly flushes the RX queue at reset time. It also ensures that the currently peeked skb is consumed before invoking mptcp_dss_corruption to prevent double consumption after reset. This resolves the recursion and reduces unnecessary workload on the kernel during subflow resets.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:52 UTC

Technical details

References

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