CVE-2026-57089 in Windows
Summary
by MITRE • 07/14/2026
Use after free in Windows SMB Server Network Transport Driver (srvnet.sys) allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 07/15/2026
The vulnerability in question represents a critical use-after-free condition within the Windows SMB Server Network Transport Driver component known as srvnet.sys. This flaw resides in the kernel-mode driver responsible for handling SMB server communications, making it a prime target for remote exploitation. The vulnerability manifests when the driver fails to properly validate memory references after objects have been freed, creating opportunities for attackers to manipulate memory contents and execute arbitrary code with system-level privileges.
The technical implementation of this use-after-free vulnerability occurs during SMB server processing operations where memory allocations are managed inefficiently. When certain network requests are processed through the srvnet.sys driver, specific data structures become vulnerable to manipulation after their referenced memory has been deallocated. Attackers can exploit this by crafting malicious SMB traffic that triggers the freed memory to be reallocated and subsequently accessed in an unauthorized manner. This pattern directly aligns with CWE-416 which specifically addresses use-after-free vulnerabilities where memory is accessed after it has been freed, potentially leading to code execution or system compromise.
From an operational perspective, this vulnerability presents significant risk as it enables remote code execution without requiring authentication or local access. The attack surface extends across all Windows systems running SMB server functionality, including Windows Server editions and workstation versions that may have SMB services enabled. The exploit potential is amplified by the fact that the vulnerability can be triggered through standard network protocols, making it suitable for automated attacks across networks. Security professionals must consider that successful exploitation could result in complete system compromise, allowing attackers to establish persistent access, escalate privileges, or deploy additional malicious payloads.
The impact of this vulnerability extends beyond immediate code execution capabilities as it fundamentally undermines the memory safety mechanisms within Windows kernel components. The srvnet.sys driver operates at the highest privilege level within the operating system, meaning any successful exploitation directly translates to system-level control. This characteristic places the vulnerability in the ATT&CK framework under the T1059.007 technique category for command and scripting interpreter, as attackers could leverage this to execute commands with complete system access. Organizations must also consider that this vulnerability may enable lateral movement within networks where SMB services are exposed or enabled on multiple systems.
Mitigation strategies should focus on immediate patching of affected Windows versions through Microsoft security updates, particularly those addressing the specific srvnet.sys driver vulnerabilities. Network segmentation and firewall rules can limit exposure by blocking SMB traffic between untrusted networks and internal systems. Additionally, implementing monitoring solutions that detect anomalous SMB traffic patterns or memory access violations may help identify exploitation attempts. Organizations should also consider disabling SMBv1 protocol where possible, as it often serves as an entry vector for similar vulnerabilities. The recommended approach includes comprehensive vulnerability assessments across all Windows systems to identify potential exposure and implementation of layered security controls that reduce the attack surface while maintaining operational functionality.