What’s Vulnerable › Vulnerabilities

CVE-2026-97523: mptcp: close race between scheduler and state change

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-25 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: close race between scheduler and state change The mptcp scheduler may race with subflow sockets state change: data transmission on the selected socket may fail and a later release could try to use mss_now reset to 0 for a divide operation. Address the issue by explicitly checking for the critical scenario.

Affected products

• Linux kernel: from 5.15.190 before 5.15.222; from 5.19.4 before 5.20; 6.0 — fixed in 5.15.222, 5.20, 7.3

How to fix

Upgrade to a fixed version: Linux kernel 5.15.222, 5.20, 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0a926b5df8efdfbac07e2fb7fafb21849a2ad9c0
• https://git.kernel.org/stable/c/42064de57fb83231fcc89663a94885f228a1ee53
• https://git.kernel.org/stable/c/4c856f3c151a2f3fa237caa651c44015916ca584
• https://git.kernel.org/stable/c/5883ae880f51edc4b1484e787473b865b6159ead
• https://git.kernel.org/stable/c/8f11430d51ff8365bc51b670bc3002b65ae4c6b7
• https://git.kernel.org/stable/c/a09c87abf10a0a7e203137c75b5381aa63d9b31d
• https://git.kernel.org/stable/c/d74b2e26b54a7dae1d87c1f19ae0d6db500e5e03

Get alerted when CVE-2026-97523 or the next vulnerability affects your stack