CVE-2023-54085
Published Dec 24, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix NULL pointer dereference on fastopen early fallback In case of early fallback to TCP, subflow_syn_recv_sock() deletes the subflow context before returning the newly allocated sock to the caller. The fastopen path does not cope with the above unconditionally dereferencing the subflow context.
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References
Frequently Asked Questions
What is CVE-2023-54085? +
In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix NULL pointer dereference on fastopen early fallback
In case of early fallback to TCP, subflow_syn_recv_sock() deletes
the subflow context before returning the newly allocated sock to
the caller.
The fastopen path does not cope with the above unconditionally
dereferencing the subflow context.
How do I check if I'm vulnerable to CVE-2023-54085? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.