CVE-2026-102199 in Windows
Summary
by MITRE • 10/13/2026
Stack-based buffer overflow in Microsoft Windows Codecs Library allows an unauthorized attacker to deny service over a network.
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability identified involves a critical stack-based buffer overflow within the Microsoft Windows Codecs Library, a core component responsible for handling various multimedia formats and image processing tasks on affected systems. This specific flaw arises from improper validation of user-supplied input data during the decoding or rendering process. When an attacker crafts maliciously formatted media files containing oversized buffers or malformed headers, they can exploit this lack of boundary checking to write data beyond the allocated stack memory space. The technical mechanism relies on overwriting adjacent memory locations, which typically includes return addresses and saved frame pointers stored on the call stack during function execution.
From a security architecture perspective, this flaw aligns with CWE-121, specifically describing a stack-based buffer overflow condition where input data exceeds the fixed-size buffer allocated for it. The exploitation of such vulnerabilities often leads to arbitrary code execution if an attacker can control the overwritten return address, directing the processor to execute shellcode injected into the memory space. However, in this specific instance, the primary reported impact is denial of service rather than remote code execution. This suggests that either the exploitability for code execution is mitigated by existing security controls such as Data Execution Prevention or Address Space Layout Randomization, or that the particular attack vector primarily targets system stability through resource exhaustion and memory corruption crashes.
The operational impact centers on the ability to cause a denial of service over a network without requiring authentication. An unauthorized attacker can target vulnerable systems remotely by delivering specially crafted media files via web servers, email attachments, or other network-accessible services that utilize the Windows Codecs Library for processing. Upon receiving and attempting to process these malicious inputs, the affected application may crash, leading to system instability, service interruption, or a complete reboot of the host machine depending on the severity of the memory corruption and the specific subsystem involved. This disrupts availability, which is one of the three pillars of information security alongside confidentiality and integrity.
In terms of threat modeling, this vulnerability can be mapped to MITRE ATT&CK techniques related to initial access via spearphishing attachment or exploitation for denial of service. Attackers may leverage this flaw as part of a broader campaign to disrupt critical infrastructure or simply as a disruptive attack against targeted organizations. The lack of authentication requirement makes it particularly dangerous in environments where media files are processed automatically, such as content management systems, email gateways, and image hosting services that do not perform deep inspection before passing data to the codec library.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Microsoft has released security updates addressing this vulnerability by patching the input validation logic within the Windows Codecs Library. System administrators should prioritize applying these patches across all affected endpoints and servers immediately. Additionally, implementing network-level defenses such as intrusion detection systems configured to detect anomalous media file patterns can provide an additional layer of protection. Organizations should also consider deploying application whitelisting or restricting the execution of untrusted scripts to limit the potential impact if a buffer overflow is successfully exploited for code execution in other contexts. Regular vulnerability scanning and penetration testing focused on multimedia processing components are recommended to identify similar weaknesses before they can be leveraged by malicious actors.