CVE-2025-59942 identifies an integer overflow vulnerability (CWE-190) in the go-f3 component of the Filecoin project, a Golang implementation of Fast Finality for Filecoin (F3). The vulnerability exists in versions 0.8.6 and below, where the validator improperly handles "poison" messages. These messages trigger an integer overflow during signer index validation, causing the go-f3 process to panic and crash the entire Filecoin node consuming these messages. The flaw does not affect confidentiality or integrity but impacts availability by causing denial of service. The vulnerability requires no authentication or user interaction but does require an attacker to send malicious messages directly to the target nodes, as the bug is in the validator and the messages do not self-propagate. The CVSS 3.1 base score is 7.5 (high), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality or integrity impact, but high availability impact. No known exploits have been reported in the wild as of the publication date. The issue is resolved in go-f3 version 0.8.7, which corrects the integer overflow handling. Given the critical role of Filecoin nodes in decentralized storage and blockchain infrastructure, this vulnerability could disrupt node operations and degrade network reliability if exploited.

For European organizations utilizing Filecoin infrastructure, this vulnerability poses a significant availability risk. A successful attack could crash Filecoin nodes, leading to denial of service conditions that disrupt decentralized storage operations and blockchain consensus processes. This could impact service providers, enterprises relying on Filecoin for data storage, and blockchain validators. While no direct data breach or integrity compromise is indicated, the downtime could cause operational delays, loss of trust, and financial impacts. The requirement for direct message delivery limits the attack surface but does not eliminate risk, especially for nodes exposed to public or semi-public networks. Organizations with critical blockchain infrastructure in Europe should consider this a high-priority issue to prevent service interruptions and maintain network stability.

The primary mitigation is to upgrade all go-f3 components to version 0.8.7 or later, where the integer overflow vulnerability is fixed. Organizations should audit their Filecoin node versions and apply patches promptly. Additionally, network-level controls should be implemented to restrict incoming messages to trusted sources, reducing exposure to malicious "poison" messages. Deploying message validation and filtering at perimeter firewalls or node gateways can help block suspicious or malformed traffic. Monitoring node logs for panic events and unusual message patterns can provide early detection of exploitation attempts. Finally, organizations should consider isolating critical Filecoin nodes within protected network segments and applying strict access controls to minimize attack vectors.