Local denial of service via MPTCP race
Published Apr 3, 2024 · Updated May 11, 2026
A race condition in Linux kernel MPTCP allows local users to cause denial of service by racing Fast Open against subflow shutdown. The subflow_simultaneous_connect helper omits FIN_WAIT2 and CLOSING from its accepted state mask even though a subflow can enter either state before subflow_state_change runs. Low-privileged local access and an MPTCP connection are required; the demonstrated reproducer triggers the kernel fault without disclosing or modifying data.
Summary
What happened
A race condition in Linux kernel MPTCP allows local users to cause denial of service by racing Fast Open against subflow shutdown. The subflow_simultaneous_connect helper omits FIN_WAIT2 and CLOSING from its accepted state mask even though a subflow can enter either state before subflow_state_change runs. Low-privileged local access and an MPTCP connection are required; the demonstrated reproducer triggers the kernel fault without disclosing or modifying data.
The record
- CVE
- CVE-2024-26708
- Published
- Apr 3, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-362, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 3, 2024CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1e777f39b4d75e599a3aac8e0f67d739474f198c <337cebbd850f94147cee05252778f8f78b8c337f
- Affected versionversion=1e777f39b4d75e599a3aac8e0f67d739474f198c <4bfe217e075d04e63c092df9d40c608e598c2ef2
- Affected versionversion=1e777f39b4d75e599a3aac8e0f67d739474f198c <e158fb9679d15a2317ec13b4f6301bd26265df2f
- Affected versionversion=6.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- syzkaller MPTCP Fast Open race reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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