What’s Vulnerable › Vulnerabilities

CVE-2024-26708: mptcp: really cope with fastopen race

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-04-03 · updated 2026-06-17
• Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: really cope with fastopen race Fastopen and PM-trigger subflow shutdown can race, as reported by syzkaller. In my first attempt to close such race, I missed the fact that the subflow status can change again before the subflow_state_change callback is invoked. Address the issue additionally copying with all the states directly reachable from TCP_FIN_WAIT1.

Affected products

• Linux kernel: from 6.2 before 6.6.18; from 6.7 before 6.7.6; 6.8-rc1, 6.8-rc2, 6.8-rc3, 6.8-rc4 — fixed in 6.6.18, 6.7.6

How to fix

Upgrade to a fixed version: Linux kernel 6.6.18, 6.7.6. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/337cebbd850f94147cee05252778f8f78b8c337f
• https://git.kernel.org/stable/c/4bfe217e075d04e63c092df9d40c608e598c2ef2
• https://git.kernel.org/stable/c/e158fb9679d15a2317ec13b4f6301bd26265df2f
• https://git.kernel.org/stable/c/337cebbd850f94147cee05252778f8f78b8c337f
• https://git.kernel.org/stable/c/4bfe217e075d04e63c092df9d40c608e598c2ef2
• https://git.kernel.org/stable/c/e158fb9679d15a2317ec13b4f6301bd26265df2f

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