CVE-2026-80076 in Office
Summary
by MITRE • 09/09/2026
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information over a network.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Office suite, specifically categorized as an out-of-bounds read error. This type of memory corruption issue arises when software attempts to access data at a memory location that is outside the boundaries of its allocated buffer or array. In the context of Microsoft Office applications, such vulnerabilities are frequently triggered by malformed documents, embedded objects, or specially crafted files designed to exploit parsing logic errors within the application's rendering engine or document processing components. When an attacker crafts input that causes the application to read beyond the intended memory limits, it can lead to the leakage of sensitive data stored in adjacent memory regions. This disclosure is not limited to local system information but extends across network boundaries if the vulnerability is exploited remotely through maliciously hosted content accessed via web browsers or email clients integrated with Office applications.
From a technical perspective, out-of-bounds reads are particularly dangerous because they can be used for reconnaissance and further exploitation phases in an attack chain. By reading arbitrary memory contents, an attacker may retrieve cryptographic keys, session tokens, passwords, or other confidential information that was previously loaded into the application's process space but not properly cleared after use. This capability aligns with CWE-125, which defines out-of-bounds read as a weakness where software reads data past the end or before the beginning of the intended buffer. The impact is severe because it compromises confidentiality without necessarily requiring code execution privileges initially. An unauthorized attacker can leverage this flaw to gather intelligence about the victim's environment, potentially facilitating more sophisticated attacks such as privilege escalation or lateral movement within an enterprise network.
The operational impact of this vulnerability extends beyond immediate data disclosure. It undermines trust in Microsoft Office products and poses significant risks to organizations that rely on these tools for daily operations. If exploited via email attachments or web-based document viewers, the attack vector is highly accessible and difficult to mitigate through user awareness alone. The ability to disclose information over a network means that remote attackers can target users without physical access or prior authentication in many scenarios. This aligns with MITRE ATT&CK techniques related to Collection and Exfiltration, specifically those involving data from local system memory or clipboard operations. Attackers may use the leaked data to perform credential stuffing attacks against other services where employees reuse passwords, thereby expanding their foothold within an organization's infrastructure.
Mitigation strategies must focus on both technical controls and procedural updates. The most effective immediate countermeasure is applying the latest security patches released by Microsoft for all affected versions of Office products. Organizations should ensure that automatic update mechanisms are enabled to reduce the window of exposure. Additionally, implementing application control policies can restrict the execution of unsigned scripts or macros within Office documents, reducing the attack surface for exploitation attempts. Network segmentation and strict e-mail filtering rules can also help prevent maliciously crafted files from reaching end-user devices. Security awareness training should emphasize caution when opening documents from unknown sources, although technical controls remain paramount given the remote nature of this vulnerability. Continuous monitoring for anomalous memory access patterns or unusual network traffic originating from Office processes can aid in early detection and response to potential exploitation attempts.