CVE-2026-80586
Published Aug 26, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: options: reset DSS fields in case of unexpected size A remote peer could send a malformed DSS with a wrong size, followed by another DSS or MPC + Data. In this case, the first suboption will be ignored, but leaving some fields written, which could lead to inconsistency or access uninitialized data. Explicitly reset the fields that could have been modified in case of unexpected size.
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References
Other References
https://git.kernel.org/stable/c/15e35fdad7a5576bf3f1c8d688877aeb5d1b506b
https://git.kernel.org/stable/c/192878df582c51d440bf7b91a15f297f29f2b596
https://git.kernel.org/stable/c/1fade1b2ac5b1a4948e538fae7313bea57b5ac36
https://git.kernel.org/stable/c/26dac5c9ffb20812b475fdf253eb04fab99cff3b
https://git.kernel.org/stable/c/27ed642a4e7e4b5df4b8522c72c457a67e052493
https://git.kernel.org/stable/c/35772b4981f38ba8059372cde8753e8e477e98ec
https://git.kernel.org/stable/c/4e80eff5c1c893aca2ac1d202f0b256d2e52ecde
https://git.kernel.org/stable/c/b1256090816ec46011601e084be580731df58fc7
Frequently Asked Questions
What is CVE-2026-80586? +
In the Linux kernel, the following vulnerability has been resolved:
mptcp: options: reset DSS fields in case of unexpected size
A remote peer could send a malformed DSS with a wrong size, followed by
another DSS or MPC + Data. In this case, the first suboption will be
ignored, but leaving some fields written, which could lead to
inconsistency or access uninitialized data.
Explicitly reset the fields that could have been modified in case of
unexpected size.
How do I check if I'm vulnerable to CVE-2026-80586? +
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.