CVE-2025-29979: 
vulnerability analysis and mitigation

CVE-2025-29979 is a heap-based buffer overflow vulnerability affecting Microsoft Office Excel, which was disclosed as part of Microsoft's May 2025 Patch Tuesday security updates. The vulnerability was initially received from Microsoft Corporation on May 13, 2025, and affects various versions of Microsoft Excel, Office 2019, Microsoft 365 Apps, and Office Long Term Servicing Channel (NVD, Wiz).

The vulnerability is classified as a Remote Code Execution (RCE) vulnerability with a CVSS v3.1 base score of 7.8 (HIGH). The technical characteristics include a local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), and user interaction required (UI:R). The scope is unchanged (S:U), with high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H). It is specifically identified as CWE-787 (Out-of-bounds Write) and CWE-122 (Heap-based Buffer Overflow) (NVD).

If successfully exploited, this vulnerability allows an unauthorized attacker to execute malicious code locally through Microsoft Excel, potentially compromising affected systems and gaining control over them (Wiz).

Microsoft has released security updates to address this vulnerability as part of the May 2025 Patch Tuesday updates. The updates are available through Microsoft Update, Microsoft Update Catalog, and Microsoft Download Center. Organizations are strongly advised to apply these security updates immediately through Windows Update or enterprise management tools (Wiz).