CVE-2026-22258 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) and CWE-770 (Allocation of Resources Without Limits or Throttling) affecting the Suricata network security monitoring engine. Suricata processes network traffic to detect intrusions and anomalies, supporting protocols including DCERPC over UDP, TCP, and SMB. The flaw arises when Suricata encounters specially crafted DCERPC packets that cause it to expand an internal buffer without limits, leading to excessive memory consumption. This uncontrolled allocation can exhaust system memory, causing Suricata to crash or be killed by the operating system, resulting in denial of service (DoS). The vulnerability affects Suricata versions prior to 7.0.14 and versions 8.0.0 up to but not including 8.0.3. Although initially reported for DCERPC over UDP, it is believed that DCERPC over TCP and SMB protocols are also vulnerable. By default, the TCP stream reassembly depth is limited to 1MiB, which mitigates the risk for DCERPC/TCP traffic, but the SMB stream reassembly depth is unlimited, increasing vulnerability exposure. The Suricata development team has patched this issue in versions 7.0.14 and 8.0.3. Mitigation options include disabling the DCERPC/UDP parser entirely or configuring the stream.reassembly.depth parameter to limit buffered data for TCP and SMB streams, though limiting SMB stream depth may reduce visibility into SMB traffic. No public exploits have been reported to date, but the vulnerability's nature makes it a significant risk for denial-of-service attacks against Suricata deployments.

For European organizations, the primary impact of CVE-2026-22258 is the potential for denial-of-service conditions on critical network security monitoring infrastructure. Suricata is widely deployed in enterprise, government, and critical infrastructure sectors across Europe for intrusion detection and prevention. An attacker capable of sending crafted DCERPC traffic could exhaust Suricata's memory resources, causing it to crash and lose visibility into network threats. This loss of monitoring can delay detection of other attacks, increasing risk to confidentiality and integrity indirectly. Organizations relying on Suricata for real-time network defense may experience operational disruptions and increased exposure to cyber threats. The impact is heightened in environments where DCERPC traffic is common, such as networks with Windows-based systems and SMB usage. Additionally, limiting SMB stream reassembly to mitigate the vulnerability may reduce visibility into SMB traffic, potentially impacting forensic and threat hunting capabilities. Given the high CVSS score (7.5) and ease of exploitation without authentication or user interaction, the threat is significant for European entities with Suricata deployments.

European organizations should immediately upgrade Suricata to versions 7.0.14 or 8.0.3 or later to apply the official patches addressing this vulnerability. Where immediate patching is not feasible, administrators should disable the DCERPC/UDP parser to prevent exploitation via UDP traffic. For DCERPC over TCP and SMB, configure the stream.reassembly.depth parameter to impose strict limits on buffered data size, balancing security and visibility needs; for SMB, carefully evaluate the impact on monitoring before reducing the default unlimited setting. Network segmentation and filtering can be employed to restrict exposure to untrusted sources sending DCERPC traffic. Monitoring Suricata logs for unusual spikes in memory usage or crashes can provide early warning of exploitation attempts. Additionally, organizations should review and harden network perimeter defenses to limit unsolicited DCERPC traffic from external sources. Regularly auditing Suricata configurations and maintaining up-to-date threat intelligence will help mitigate risks associated with this vulnerability.