CVE-2026-70130
Summary
by MITRE • 08/11/2026
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 08/11/2026
A heap-based buffer overflow vulnerability exists within Microsoft Office applications that enables arbitrary code execution by unauthenticated attackers who can manipulate the target system. This critical security flaw resides in the memory management mechanisms of office software components, specifically affecting how the application handles dynamic memory allocation and data processing. The vulnerability manifests when maliciously crafted input is processed through office document parsing functions, leading to improper memory boundary checks during heap allocation operations. Attackers can exploit this weakness by crafting specially formatted Office documents that trigger the buffer overflow condition when opened or processed by vulnerable applications.
The technical implementation of this vulnerability follows a classic heap-based buffer overflow pattern where insufficient bounds checking allows attackers to overwrite adjacent memory locations within the heap memory space. This memory corruption typically occurs during document parsing operations involving complex data structures such as tables, charts, or embedded objects that require dynamic memory allocation. The flaw enables attackers to manipulate heap metadata and potentially redirect execution flow through controlled memory overwrites. According to cwe standards, this represents a direct instance of cwe-121 heap-based buffer overflow vulnerability category, which falls under the broader classification of memory safety issues.
The operational impact of this vulnerability extends beyond simple code execution capabilities to encompass complete system compromise potential when combined with other exploitation techniques. An attacker who successfully exploits this vulnerability can gain unauthorized access to the target system with the privileges of the compromised user account. The attack typically requires social engineering to deliver malicious Office documents to unsuspecting users, making it particularly dangerous in enterprise environments where document sharing is common. Modern exploit mitigation techniques such as address space layout randomization and data execution prevention may be bypassed through sophisticated exploitation methods that leverage information leakage or partial control over the heap layout.
Organizations should implement immediate mitigations including applying all available security patches from microsoft security response center, deploying application whitelisting solutions to restrict execution of untrusted Office documents, and implementing network-based intrusion detection systems to monitor for suspicious document handling activities. Additionally, users should be trained to recognize phishing attempts and avoid opening unsolicited office documents from unknown sources. The vulnerability aligns with attack techniques described in the attack pattern taxonomy under the application layer exploitation category, specifically targeting the privilege escalation and code execution phases of cyber attacks. Regular security assessments and vulnerability scanning should include checks for outdated Microsoft Office installations that may be susceptible to this heap-based buffer overflow condition.