CVE-2026-97760 in Office
Summary
by MITRE • 10/15/2026
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network.
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Analysis
by VulDB Data Team • 10/15/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Office Excel application, specifically categorized as an out-of-bounds read condition. This type of memory corruption error occurs when software attempts to access data at a memory location that lies outside the boundaries of the intended buffer or array structure. In the context of Excel, this typically arises during the parsing and rendering of complex spreadsheet files containing specially crafted formulas, embedded objects, or malformed metadata structures. When an attacker constructs a malicious document designed to exploit these specific edge cases in the application's internal logic, they can trigger the erroneous memory access sequence that leads to the disclosure of sensitive information residing in adjacent memory regions.
From a technical perspective, out-of-bounds reads are particularly dangerous because they allow for non-destructive data exfiltration without necessarily crashing the host system immediately. Unlike buffer overflows which often lead to arbitrary code execution through stack smashing or heap corruption, an out-of-bounds read primarily facilitates information disclosure. The attacker can leverage this flaw to leak internal pointers, cryptographic keys, session tokens, or other sensitive user data that resides in memory adjacent to the targeted buffer. This capability significantly lowers the barrier for exploitation as it does not require precise control over execution flow, making it a potent vector for initial access and reconnaissance phases within an attack chain.
The operational impact of this vulnerability is severe due to its potential for remote code execution precursors and data theft via network vectors. Since Microsoft Office applications are ubiquitous in enterprise environments, the availability of exploit kits targeting Excel increases the risk profile substantially. An unauthorized attacker can distribute a malicious spreadsheet through phishing emails or compromised websites. Upon opening the file by an unsuspecting user with appropriate privileges, the vulnerability is triggered, allowing the attacker to read sensitive information from the victim's machine memory and transmit it over the network. This compromises confidentiality integrity and potentially aids in further lateral movement within a corporate network if internal credentials or configuration details are exposed.
This flaw aligns closely with Common Weakness Enumeration (CWE) identifiers such as CWE-125, which defines out-of-bounds read errors involving reading data beyond the end of an array or buffer. Furthermore, from the perspective of the MITRE ATT&CK framework, this vulnerability supports techniques related to Initial Access via Spearphishing Attachment and Credential Dumping through Memory Scraping if sensitive credentials are present in memory at the time of exploitation. The ability to disclose information over a network also touches upon data exfiltration pathways that adversaries use to maintain persistence or escalate privileges after gaining initial foothold access within an organization's infrastructure.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements. Organizations should prioritize applying the latest security updates released by Microsoft for all instances of Office Excel, as these patches typically include bounds checking enhancements and input validation fixes that prevent the malformed structures from triggering the memory error. Additionally, implementing application control policies can restrict the execution of untrusted scripts or macros within office documents, thereby reducing the attack surface even if a vulnerability is present. Users should be educated to exercise caution when opening files received via email or downloaded from unverified sources, and security teams should deploy endpoint detection and response solutions capable of identifying anomalous memory access patterns indicative of exploitation attempts in real time.