CVE-2026-98432 is already fixed in the upstream Linux kernel, but Ubuntu has not shipped a patched kernel yet, and Ubuntu 24.04 is the setup Anza lists in its validator requirements. Solana Foundation validator relations lead Tim Garcia posted interim steps for Ubuntu operators, and Anza amplified the guidance to mainnet-beta validators.

The temporary mitigations: block inbound TCP packets that carry IPv4 options, disable Multipath TCP (MPTCP) and turn off TCP request-socket migration. Operators should keep them in place until Ubuntu releases the fixed kernel, then reboot and confirm the patched version is running.

The flaw is rated 9.8 out of 10 and can be exploited without authentication or user interaction, giving attackers root access to the server.

Ubuntu's tracker still marks the 24.04 kernel as vulnerable, with version 6.8.0-149.149 named as the planned fix. Amazon Linux has already shipped corrected kernels. No Solana validator compromise through the flaw has been reported so far.