Hacker News

Go programs enable MPTCP by default, exposing them to Linux CVE-2026-98432(groups.google.com)

9 points by acossta 6 hours ago | 4 comments

Unfortunate news for Caddy which exposes unpatched Linux systems (confirmed) and may be common in container setups. Unclear if the container engine as a middle man actually helps mitigate the issue.

[–] fractorial 5 hours ago

From TFA:

> Note that disabling MPTCP on a program-by-program basis is a fragile mitigation. Accidentally leaving a single MPTCP listener exposed will still leave a system vulnerable. Further, it assumes that all viable exploits for this bug depend on MPTCP. Again, we strongly recommend upgrading to a patched kernel version

[–] commandersaki 3 hours ago

Does `sysctl -w net.mptcp.enabled=0` work?

[–] nialse 5 hours ago

The title is highlighting an unexpected exposure path. (Not my submission.) An unfortunately common combination. Agreed that the issue is in Linux, somehow the go surface area makes the situation much worse though.