The Solana Foundation warned validators about a critical Linux vulnerability allowing remote command execution. Fixes are pending for affected systems.
The Solana Foundation has issued a warning to its validators regarding a severe vulnerability in the Linux kernel, identified as CVE-2026-98432. This flaw allows attackers to execute commands remotely on servers without authentication under certain conditions. Tim Garcia, the validator relations lead at the Solana Foundation, notified the community about the vulnerability's status and provided guidance for those using Ubuntu.
"Validators! CVE-2026-98432 is patched in the linux kernel but not yet patched on ubuntu. Here’s what you need to do if you’re running ubuntu:" — Tim Garcia (@TimGarcia0) November 2, 2026
The vulnerability received a critical score of 9.8 out of 10 on the CVSS 3.1 scale, stemming from a race condition in the IPv4 network subsystem that handles TCP connections. This flaw could lead to kernel memory corruption when attackers send precisely timed network requests, which may result in server crashes or arbitrary code execution.
Present in Linux kernels since version 4.4, released in 2016, fixes have been prepared for some branches but are not yet available across all distributions. Specifically, as of November 2, Ubuntu versions 22.04, 24.04, 26.04, and 26.10 remain vulnerable, with updates still in development.
Garcia advised Solana validators running Ubuntu to temporarily limit the handling of certain network packets and disable Multipath TCP and TCP connection migration until the updates are released. It's important to note that this vulnerability does not directly affect Solana's code but targets the operating systems used by validators and other network applications. A compromised validator could disrupt operations but would not necessarily lead to a breach of the blockchain itself.
Researchers Showcase Remote Exploit
On October 27, experts from Anthropic demonstrated a successful exploitation of CVE-2026-98432 using their internal research model. In a lab setting, they created a two-stage attack on a Linux server with an active Multipath TCP listener, granting root access without user credentials.
The first phase of the attack revealed the kernel's memory location and bypassed the KASLR protection mechanism, while the second phase executed commands as root using the same vulnerability. Anthropic noted that the first phase took about 48 minutes, followed by five minutes for the second, although they did not disclose the attack code publicly.
Amazon Web Services has released patches for Amazon Linux 2 and Amazon Linux 2023 but currently has no information on the real-world exploitation of CVE-2026-98432.
In a related incident, Solflare, a cryptocurrency wallet, reported an issue with validator keys involving a third-party staking provider, affecting a node that had attracted approximately 1.56 million SOL worth around $160 million. Fortunately, the assets remained safe, and the company pledged to compensate users who transition their stake to a new validator.
