CVE-2025-49696
Published: 08 July 2025
Summary
CVE-2025-49696 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 8.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 25.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly requires identification, reporting, and timely patching of known flaws like this out-of-bounds read vulnerability in Microsoft Office.
Implements memory safeguards such as ASLR and DEP that prevent exploitation of heap-based buffer overflow vulnerabilities leading to local code execution.
Ensures receipt of vendor security advisories like Microsoft's update guide for CVE-2025-49696 to enable prompt flaw remediation.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Out-of-bounds read/heap overflow in Office enabling local unauthenticated code execution directly facilitates T1068 Exploitation for Privilege Escalation.
NVD Description
Out-of-bounds read in Microsoft Office allows an unauthorized attacker to execute code locally.
Deeper analysisAI
CVE-2025-49696 is an out-of-bounds read vulnerability affecting Microsoft Office, mapped to CWE-122 (Heap-based Buffer Overflow) and CWE-125 (Out-of-bounds Read). Published on 2025-07-08, it carries a CVSS v3.1 base score of 8.4 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). The issue enables an unauthorized attacker to execute code locally on the affected system.
A local attacker can exploit this vulnerability with low attack complexity, requiring no privileges or user interaction. Upon successful exploitation, the attacker achieves high-impact effects, gaining unauthorized code execution that fully compromises confidentiality, integrity, and availability on the local system.
Microsoft's update guide provides details on mitigation and patches for CVE-2025-49696, available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49696. Security practitioners should consult this advisory for deployment instructions.
Details
- CWE(s)