CVE-2025-64331 is a stack-based buffer overflow vulnerability classified under CWE-121, affecting the Suricata network intrusion detection and prevention system developed by the Open Information Security Foundation (OISF). Suricata inspects network traffic for malicious activity and is widely used for network security monitoring (NSM). This vulnerability arises when Suricata processes large HTTP file transfers under specific configurations: when the HTTP response body size limit is increased beyond default values and when logging of printable HTTP bodies is enabled. Under these conditions, Suricata fails to properly handle the size of the HTTP response body, leading to a stack overflow. This overflow can cause Suricata to crash, resulting in a denial of service (DoS) condition. The vulnerability does not affect confidentiality or integrity directly but impacts availability by disrupting network monitoring capabilities. The CVSS v3.1 base score is 7.5 (high), reflecting the network attack vector, low attack complexity, no privileges required, no user interaction, and an impact limited to availability. The flaw affects Suricata versions prior to 7.0.13 and 8.0.2, with patches released in these versions to address the issue. No known exploits have been reported in the wild to date. A practical workaround involves reverting to default HTTP response body limits and disabling the logging of printable HTTP bodies, which is disabled by default. This mitigates the risk until patches can be applied. Given Suricata’s role in network defense, this vulnerability could be leveraged by attackers to disrupt security monitoring, potentially allowing malicious traffic to go undetected during outages.

For European organizations, the primary impact of CVE-2025-64331 is the potential disruption of network intrusion detection and prevention capabilities, which could lead to reduced visibility into malicious network activity. This denial of service could be exploited by threat actors to evade detection during critical attacks, increasing the risk of successful breaches. Organizations in sectors with high reliance on Suricata for network security—such as telecommunications, finance, government, and critical infrastructure—face heightened risk. The disruption could affect incident response times and overall security posture. Additionally, regulatory compliance frameworks in Europe, such as GDPR and NIS Directive, require robust security monitoring; failure to maintain operational IDS/IPS systems could result in compliance violations and associated penalties. The vulnerability’s remote exploitability without authentication means attackers can trigger the issue from outside the network, increasing the threat surface. Although no data confidentiality or integrity loss is expected, the availability impact alone can have cascading effects on organizational security and operational continuity.

European organizations should prioritize upgrading Suricata installations to versions 7.0.13 or 8.0.2 or later, where the vulnerability is patched. Until upgrades can be performed, administrators should revert any increased HTTP response body limits to default values and disable the logging of printable HTTP bodies, which is off by default, to prevent triggering the overflow. Network security teams should monitor Suricata logs and system stability closely for signs of crashes or abnormal behavior. Implementing network segmentation and filtering to limit exposure of Suricata sensors to untrusted traffic can reduce risk. Additionally, organizations should conduct internal audits to identify all Suricata deployments, including embedded or less visible instances, to ensure comprehensive patching or mitigation. Incident response plans should be updated to address potential IDS/IPS outages. Finally, security teams should stay alert for any emerging exploit code or attack campaigns targeting this vulnerability and be prepared to respond swiftly.